Chapter 6. Gait and Posture Analysis

At the completion of this chapter, the reader will be able to:

1. Summarize the various components of the gait cycle.

2. Apply the knowledge of gait components to gait analysis.

3. Perform a comprehensive gait analysis.

4. Categorize the various compensations of the body and their influences on gait.

5. Recognize the manifestations of abnormal gait and develop strategies to counteract these abnormalities.

6. Describe and demonstrate a number of abnormal gait syndromes.

7. Make an accurate judgment when recommending an assistive device to improve gait and function.

8. Describe and demonstrate the various gait patterns used with assistive devices.

9. Evaluate the effectiveness of an intervention for a gait dysfunction.

10. Summarize the components of a postural assessment.

11. Perform a thorough posture assessment.

12. Recognize the most common manifestations of abnormal posture.

13. Make an accurate judgment when recommending postural adjustments.

14. Evaluate the effectiveness of a postural adjustment.

The assessment of symmetry within locomotion and posture is critical in the evaluation of neuromusculoskeletal dysfunction. For most individuals, gait or posture is an innate characteristic, as much a part of their personality as their smile. Indeed, many people can be recognized in a group by their gait or posture. The purpose of this chapter is to describe the various components of gait and posture and to provide the clinician with the necessary tools for the analysis of each.

Gait and the Gait Cycle

The lower kinetic chain has two main functions: to provide a stable base of support (BOS) in standing and to propel the body through space with gait. While maintaining a static equilibrium of forces, the objective with mobility is to create and control dynamic, unbalanced forces to produce movement. 1Gait is thus an example of controlled instability. It is not clear whether gait is learned or is preprogrammed at the spinal cord level. However, once mastered, gait allows us to move around our environment in an efficient manner, requiring little in the way of conscious thought, at least in familiar surroundings. Bipedal gait has allowed the arms and hands to be free for exploration of the environment. Even though gait appears to be a simple process, it is prone to breakdown. Although individual gait patterns are characterized by significant variation, three essential requirements have been identified for locomotion: progression, postural control, and adaptation: 2

• Progression. The fall that occurs at the initiation of gait so that an individual must take the first step is controlled by the central nervous system (CNS). 3The CNS computes in advance the required size and direction of this fall toward the supporting foot. Progression of the head, arms, and trunk is initiated and terminated in the brain stem that maintains a central pattern generator (CPG) through the spinal cord (see Chapter 3). The locomotor CPG produces self-sustaining patterns of stereotype motor output resulting in gait-like movements. In addition, gait relies on the control of the limb movements by reflexes. Two such reflexes include the stretch reflex and the extensor thrust. The stretch reflex is involved in the extremes of joint motion, whereas the extensor thrust may facilitate the extensor muscles of the lower extremity during weight bearing. 4Both the CPG and the reflexes that mediate afferent input to the spinal cord are under the control of the brainstem and are therefore subconscious. 5This would tend to indicate that verbal coaching (i.e., feedback that is processed in the cortex) regarding an aberrant gait pattern might be less effective than a sensory input that will elicit a brain stem-mediated postural response. 1
• Postural control. Postural control is dynamically maintained to appropriately position the body for efficient gait.
• Adaptation. Although central pattern generation occurs independent of sensory input, afferent information from the periphery can influence the CPG. Adaptation is achieved by adjusting the central pattern generated to meet task demands and environmental demands.

Gait, therefore, is initiated grossly in the spinal cord and fine tuned by the higher brain centers. 1In patients who have developed dysfunctional gait patterns, physical therapy can help to restore this exquisite evolutionary gift. 6Pain, weakness, and disease can all cause a disturbance in the normal rhythm of gait. However, except in obvious cases, abnormal gait does not always equate with impairment.

In addition to neural input, normal human gait also involves a complex synchronization of the cardiopulmonary and muscular systems in which the cardiopulmonary system produces the energy required for gait.

Walking involves the alternating action of the two lower extremities. This walking pattern is studied as a gait cycle. The gait cycleis defined as the interval of time between any of the repetitive events of walking. Such an event could include the point when the foot first contacts the ground to the point when the same foot contacts the ground again. 7The gait cycle consists of two phases ( Fig. 6-1):

1. Stance.This phase constitutes approximately 60–65% of the gait cycle 8, 9and describes the entire time the foot is in contact with the ground and the limb is bearing weight. The stance phase begins when the foot makes contact with the ground and concludes when the ipsilateral foot leaves the ground. The stance phase takes about 0.6 seconds during an average walking speed.

2. Swing.The swing phase constitutes approximately 35–40% of the gait cycle 8, 9and describes the phase when the foot is not in contact with the ground. The swing phase begins as the foot is lifted from the ground and ends when the ipsilateral foot makes contact with the ground again. 7

Stance Phase

Within the stance phase, two tasks and five intervals are recognized. 8, 10, 11The two tasks are weight acceptance and single-limb support. The five intervals are initial contact, loading response, midstance, terminal stance, and preswing 11( Fig. 6-2). Initial contact and toe-off are instantaneous events. The initial contact, which occurs when one foot makes contact with the ground, takes place at the beginning of the stance phase. As the initial contact of one foot is occurring, the contralateral foot is preparing to come off the floor.

Weight Acceptance

The weight acceptance task includes the intervals of initial contact and loading response. The initial contact interval accounts for the first 10% of the gait cycle and describes the phase when one foot is coming off the floor while the other foot is accepting body weight and absorbing the shock of initial contact. Because both feet are in contact with the floor, this phase is referred to as double supportor the initial double stancephase. 11The loading responseinterval begins as one limb bears weight while the other leg begins to go through its swing phase.

Single-Leg Support

The single-legged support task includes the three intervals of midstance, terminal stance, and preswing.

The midstanceinterval, representing the first half of the single-limb support task, begins as one foot is lifted and continues until the body weight is aligned over the forefoot. 11The loading response and midstance intervals account for the next 40% of the gait cycle. 11

The terminal stanceinterval is the second half of the single-limb support task. It begins when the heel of the weight-bearing foot lifts off the ground and continues until the contralateral foot strikes the ground.

The preswinginterval begins with initial contact of the contralateral limb and ends with the ipsilateral toe-off. During this phase, the stance leg is unloading the body weight to the contralateral limb and preparing the leg for the swing phase. The terminal stance and preswing intervals account for the next 10% of the gait cycle. 11Because both feet are on the floor at the same time during this interval, double support occurs for the second time in the gait cycle. This last portion of the stance phase is, therefore, referred to as the terminal double stance. The phase of single-limb support of one limb equals the phase of swing for the other. 11

Swing Phase

Gravity and momentum are the primary sources of motion for the swing phase. 4Within the swing phase, one task and three intervals are recognized. 8, 10, 11The task involves limb advancement. The three intervals are initial swing, midswing, and terminal swing. 11

Limb Advancement

The swing phase involves the forward motion of the nonweight-bearing (NWB) foot. The three intervals of the swing phase include the following: 11

1. Initial swing.This interval begins with the lifting of the foot from the floor and ends when the swinging foot is opposite the stance foot. It represents the 60–73% phase of the gait cycle. 11

2. Midswing.This interval begins as the swinging limb is opposite the stance limb and ends when the swinging limb is forward and the tibia is vertical. It represents the 73–87% phase of the gait cycle. 11

3. Terminal swing.This interval begins with a vertical tibia of the swing leg with respect to the floor and ends the moment the foot strikes the floor. It represents the last 87–100% of the gait cycle.

The precise duration of the gait cycle intervals depends on a number of factors, including age, impairment, and the patient's walking velocity. Velocity is defined as the distance a body moves in a given time and is thus calculated by dividing the distance traveled by the time taken. Normal free gait velocity on a smooth and level surface averages about 62 m/min for adults, with men being about 5% faster than women. 12As gait speed increases, it develops into jogging and then running, with changes in each of the intervals. For example, as speed increases, the stance phase decreases and the terminal double stance phase disappears altogether. This produces a double unsupported phase. 13Although the motion occurring at each of the lower extremity joints is similar for walking and for running, the required range of motion increases with the speed of the activity.

A normal gait pattern is a factor of a number of parameters.

Step Width

The step width is the distance between both feet. The normal step width, which is considered to be between 5 and 10 cm (2–4 in.), forms the BOS during gait. The size of the BOS and its relation to the center of gravity (COG) are important factors in the maintenance of balance and, thus, the stability of an object. The COG must be maintained over the BOS, if equilibrium is to be maintained. The BOS includes the part of the body in contact with the supporting surface and the intervening area. 14As the COG moves forward with each step, it briefly passes beyond the anterior margin of the BOS, resulting in a temporary loss of balance. 14This temporary loss of equilibrium is counteracted by the advancing foot at initial contact, which establishes a new BOS. A larger than normal step width or BOS is observed in individuals who have muscle imbalances of the lower limbs and trunk, as well as those who have problems with overall static dynamic balance. 15Assistive devices, such as crutches or walkers, can be prescribed to increase the BOS and, therefore, enhance stability. The step width should be seen to decrease to around zero with increased speed. If the step width decreases to a point below zero, crossover occurs, whereby one foot lands where the other should, and vice versa. 16

Step Length

Step length is measured as the distance between the point of initial contact of one foot and the point of initial contact of the opposite foot. The average step length is about 72 cm (28 in.). The measurement should be equal for both legs.

Stride Length

Stride length is the distance between successive points of foot-to-floor contact of the same foot. A stride is one full lower extremity cycle. Two step lengths added together make the stride length. The average stride length for normal adults is 144 m (56 in.). 12

Typically, the step and stride lengths do not vary more than a few centimeters between tall and short individuals. Men typically have longer step and stride lengths than women. Step and stride lengths decrease with age, pain, disease, and fatigue. 17, 18A decrease in step or stride length may also result from a forward head posture, a stiff hip, or a decrease in the availability of motion at the lumbar spine. The decrease in step and stride length that occurs with aging is thought to be the result of a number of factors including an overall decrease in joint range of motion, and the increased likelihood of falling during the swing phase of ambulation, caused by diminished control of the hip musculature. 19This lack of control prevents the aged person from being able to intermittently lose and recover the same amount of balance that the younger adult can lose and recover. 19

Cadence

Cadence is defined as the number of separate steps taken in a certain time. Normal cadence is between 90 and 120 steps per minute. 20, 21The cadence of women is usually six to nine steps per minute slower than that of men. 14Cadence is also affected by age, decreasing from the age of 4 to the age of 7 years, and then again in advancing years. 22

Velocity

The primary determinants of gait velocity are the repetition rate (cadence), physical conditioning, and the length of the person's stride. 12

Vertical Ground Reaction Forces

Newton's third law states that for every action there is an equal and opposite reaction. During gait, vertical ground reaction forces are created by a combination of gravity, body weight, and the firmness of the ground. Under normal conditions, we are mostly unaware of these forces. However, in the presence of joint inflammation or tissue injury, the significance of these forces becomes apparent. Vertical ground reaction force begins with an impact peak of less than body weight and then exceeds body weight at the end of the initial contact interval, dropping during midstance and rising again to exceed the body weight, reaching its highest peak during the terminal stance interval. Thus, there are two peaks of ground reaction force during the gait cycle: the first at maximum limb loading during the loading response and the second during terminal stance.

The ground reaction force vector changes from anterior to the hip joint at initial contact to a progressively posterior position at late stance, when the ground reaction force is posterior to the hip. 32, 33Peak flexion torque occurs at initial contact but gradually declines, changing to an extension torque in midstance. The extension torque remains until terminal stance. 32, 33

During the gait cycle, the tibiofemoral joint reaction force has two peaks: the first immediately following initial contact (two to three times body weight) and the second during preswing (three to four times body weight). 34Tibiofemoral joint reaction forces increase to five to six times body weight for running and stair climbing, and eight times body weight with downhill walking. 34– 36

It is well established that joint angles and ground reaction force components increase with walking speed. 37This is not surprising, because the dynamic force components must increase as the body is subjected to increasing deceleration and acceleration forces when walking speed increases.

Mediolateral Shear Forces

Mediolateral shear in walking gait begins with an initial medial shear (occasionally lateral) after initial contact, followed by lateral shear for the remainder of the stance phase. 32, 33At the end of the stance phase, the shear shifts to a medial direction because of propulsion forces.

Anteroposterior Shear Forces

Anteroposterior shear forces in gait begin with an anterior shear force at initial contact and the loading response intervals, and a posterior shear at the end of the terminal stance interval.

Much has been written about the criteria for normal and abnormal gait. 7, 9, 24, 32, 39– 44Although the presence of symmetry in gait appears to be important, asymmetry in itself does not guarantee impairment. It must be remembered that the definition of what constitutes the so-called normal gait is elusive. Unlike posture, which is a static event, gait is dynamic and as such is protean.

Gait involves the displacement of body weight in a desired direction, utilizing a coordinated effort between the joints of the trunk and extremities and the muscles that control or produce these motions. Any interference that alters this relationship may result in a deviation or disturbance of the normal gait pattern. This, in turn, may result in increased energy expenditure or functional impairment.

Perry 20lists four prioritiesof normal gait:

1. Stability of the weight-bearing foot throughout the stance phase.

2. Clearance of the NWB foot during the swing phase.

3. Appropriate prepositioning (during terminal swing) of the foot for the next gait cycle.

4. Adequate step length.

Gage 22added a fifth priority, energy conservation. The typical energy expended in normal gait (2.5 kcal/min) is less than twice that spent while sitting or standing (1.5 kcal/min). 22Two-dimensional kinetic data have revealed that approximately 85% of the energy for normal walking comes from the plantar flexors of the ankle, and 15% from the flexors of the hip. 46It has been proposed that the type of gait selected is based on metabolic energy considerations. 47Current commonly used parameters to measure walking efficiency include oxygenconsumption, heart rate, and comfortable speed of walking. 48– 50Economy of mobility is a measurement of submaximal oxygen uptake (submax VO 2) for a given speed. 51, 52A decline in functional performance may be evidenced by an increase in submax VO 2for walking. 53This change in economy of mobility may be indicative of an abnormal gait pattern. 53Some researchers have reported no gender differences for economy of mobility, 54– 56whereas others suggest that men are more economical or have lower energy costs than women at the same work. 57– 59Age-related declines in economy of mobility also have been reported in the literature, with differing results. Some researchers reported that older adults were less economical than younger adults while walking at various speeds. 51, 60, 61Conversely, economy of mobility appears to be unaffected by aging for individuals who maintain higher levels of physical activity. 62– 64

Some authors have claimed that a limb-length discrepancy leads to mechanical and functional changes in gait 65and increased energy expenditure. 66Intervention has been advocated for limb-length discrepancies of less than 1 cm to discrepancies greater than 5 cm, 65– 67but the rationale for these recommendations has not been well defined, and the literature contains little substantive information regarding the functional significance of these discrepancies. 68For example, Gross found no noticeable functional or cosmetic problems in a study of 74 adults who had less than 2 cm of discrepancy and 35 marathon runners who had as much as 2.5 cm of discrepancy. 67

For gait to be efficient and to conserve energy, the COG* must undergo minimal displacement:

• Any displacement that elevates, depresses, or moves the COG beyond normal maximum excursion limits wastes energy.
• Any abrupt or irregular movement will waste energy even when that movement does not exceed the normal maximum displacement limits of the COG.

*The COG of the body is located approximately at midline in the frontal plane and slightly anterior (5 cm or 2 in.) to the second sacral vertebra in the sagittal plane.

To minimize the energy costs of walking, the body uses a number of biomechanical mechanisms. In 1953, Saunders, Inman, and Eberhart 71proposed that six kinematic features—the Six Determinants—have the potential to reduce the energetic cost of human walking. The six determinants are as follows: 72

• Lateral displacement of the pelvis: To avoid significant muscular and balancing demands, the pelvis shifts side to side (approximately 2.5–5 cm or 1–2 in.) during the gait cycle in order to center the weight of the body over the stance leg. If the lower extremities dropped directly vertical from the hip joint, the center of mass would be required to shift 3–4 in. to each side to be positioned effectively over the supporting foot. The combination of femoral varus and anatomical valgum at the knee permits a vertical tibial posture with both tibias in close proximity to each other. This narrows the step width to 5–10 cm (2–4 in.) from heel center to heel center, thereby reducing the lateral shift required of the COG toward either side.
• Pelvic rotation: The rotation of the pelvis normally occurs about a vertical axis in the transverse plane toward the weight-bearing limb. The total pelvic rotation is approximately 4 degrees to each side. 22Forward rotation of the pelvis on the swing side prevents an excessive drop in the body's COG. The pelvic rotation also results in a relative lengthening of the femur by lessening the angle of the femur with the floor, and thus step length, during the termination of the swing period. 11
• Vertical displacement of the pelvis: Vertical pelvic shifting keeps the COG from moving superiorly and inferiorly more than 5 cm (2 in.) during normal gait ( Fig. 6-3). Due to the shift, the high point occurs during midstance, and the low point occurs during initial contact. The amount of vertical displacement of the pelvis may be accentuated in the presence of a leg length discrepancy, fusion of the knee, or hip abductor weakness, the latter of which results in a Trendelenburg sign. The Trendelenburg sign is said to be positive if, when standing on one leg, the pelvis drops on the side opposite to the stance leg. The weakness is present on the side of the stance leg—the gluteus medius is not able to maintain the COG on the side of the stance leg.
• Knee flexion in stance: Knee motion is intrinsically associated with foot and ankle motion. At initial contact before the ankle moves into a plantarflexed position, and thus is relatively more elevated, the knee is in relative extension. Responding to a plantarflexed posture at loading response, the knee flexes. Midstance knee flexion prevents an excessive rise in the body's COG during that period of the gait cycle. If not for the midstance knee flexion, the COG's rise during midstance would be larger, as would its total vertical displacement. Passing through midstance as the ankle remains stationary with the foot flat on the floor, the knee again reverses its direction to one of extension. As the heel comes off the floor in terminal stance, the heel begins to rise as the ankle plantarflexes and the knee flexes. In preswing, as the forefoot rolls over the metatarsal heads, the heel elevates even more as further plantarflexion occurs and flexion of the knee increases.
• Ankle mechanism: For normal foot function and gait, the amount of ankle joint motion required is approximately 10 degrees of dorsiflexion (to complete midstance and begin terminal stance) and 20 degrees of plantarflexion (for full push off in preswing). At initial contact, the foot is in relative dorsiflexion due to the muscle action of the pretibial muscles and the triceps surae. This muscle action produces a relative lengthening of the leg, resulting in a smoothing of the pathway of the COG during stance phase.
• Foot mechanism: The controlled lever arm of the forefoot at preswing is particularly helpful as it rounds out the sharp downward reversal of the COG. Thus it does not reduce a peak displacement period of the COG as the earlier determinants did but rather smoothes the pathway. An adaptively shortened gastrocnemius muscle may produce movement impairment by restricting normal dorsiflexion of the ankle from occurring during the midstance to heel raise portion of the gait cycle. This motion is compensated for by increased pronation of the subtalar joint, increased internal rotation of the tibia, and resultant stresses to the knee joint complex.

Joint Motions

During the gait cycle, the swing of the arms is out of phase with the legs. As the upper body moves forward, the trunk twists about a vertical axis. The thoracic spine and the pelvis rotate in opposite directions to each other to enhance stability and balance. In contrast, the lumbar spine tends to rotate with the pelvis. The shoulders and trunk rotate out of phase with each other during the gait cycle. 73Unless they are restrained, the arms tend to swing in opposition to the legs, the left arm swinging forward as the right leg swings forward, and vice versa. 4When the arm swing is prevented, the upper trunk tends to rotate in the same direction as the pelvis, producing an awkward gait.

Maximum flexion of both the elbow and the shoulder joints occurs at the initial contact interval of the opposite foot, and maximum extension occurs at the initial contact of the foot on the same side. 77

Although the majority of the arm swing results from momentum, the pendular actions of the arms are also produced by gravity and muscle action. 4, 78

• The posterior deltoid and teres major appear to be involved during the backward swing.
• The posterior deltoid serves as a braking mechanism at the end of the forward swing.
• The middle deltoid is active in both the forward and the backward swing, perhaps to prevent the arms from brushing against the sides of the body during the swing.

The motions that occur at each of the lower extremity joints during the stance phase of the gait cycle are outlined in Table 6-2and Fig. 6-4.

Hip

The function of the hip is to extend the leg during the stance phase and flex the leg during the swing phase ( Table 6-2). Hip motion occurs in all three planes during the gait cycle.

• The hip rotates approximately 40–45 degrees in the sagittal plane during a normal stride, beginning in external rotation at initial contact. 33The hip begins to internally rotate during the loading response. Maximum internal rotation is reached just before midstance. The hip externally rotates during the swing phase, with maximal external rotation occurring in terminal swing. 32
• The hip flexes and extends once during the gait cycle, with the limit of flexion occurring at the middle of the swing phase, and the limit of extension being achieved before the end of the stance phase ( Table 6-2). Maximum hip flexion of 30–35 degrees occurs in late swing phase at about 85% of the gait cycle; maximum extension of approximately 10 degrees is reached near toe-off at approximately 50% of the cycle. 32, 33, 79The ligaments of the hip helps to stabilize the joint in extension.
• In the coronal plane, hip adduction occurs throughout early stance and reaches a maximum at 40% of the cycle 79Hip adduction totaling 5–7 degrees occurs in early swing phase, which is followed by slight hip abduction at the end of the swing phase, especially if a long stride is taken. 32, 33, 79Perry reports that the total transverse plane motion is 8 degrees. 33

The greatest force on the hip occurs during midstance. Painful hip, knee, or ankle conditions cause this interval to be shortened to decrease the time spent in the painful position.

Knee

The knee flexes twice and extends twice during each gait cycle: once during weight bearing and once during NWB.

The knee flexes to about 20 degrees during the loading response interval, and this acts as a shock-absorbing mechanism. The knee then begins to extend, and as the heel rises during the terminal stance interval, it is almost fully extended, but flexes again as the swing phase begins. The flexion occurs so that the lower limb can be advanced during the swing phase with minimum vertical displacement of the COG. The knee then continues to flex as the leg moves into the swing phase, before extending again prior to initial contact. 7In normal walking, about 60 degrees of knee motion is required for adequate clearance of the foot during the swing phase. This peak flexion is required immediately after toe-off because at that point in the gait cycle, the toe is still pointed toward the ground. 22

The arthrokinematics involved during the loading response include an anterior gliding of the femoral condyles, which serves to “unlock” the knee. This forward gliding is controlled by the passive restraint of the posterior cruciate ligament (PCL) and by the active contraction of the quadriceps muscles.

A loss of knee extension, which can occur with a flexion deformity, results in the hip being unable to extend fully, which can alter the gait mechanics. Patients with patellofemoral dysfunction demonstrate less knee flexion than normal in the stance phase of gait, combined with increased external rotation of the femur during the swing phase. 42Excessive compensatory internal rotation of the femur of the weight-bearing leg during the stance phase may result in abnormal stresses being placed on the patellofemoral joint. 42

Foot and Ankle

Ankle joint motion during the gait cycle occurs primarily in the sagittal plane. During normal gait, the initial contact with the ground is made by the heel. In individuals with poor control of dorsiflexion (e.g., hemiplegics), the initial contact is made with the lower part of the heel and forefoot simultaneously. This is usually accompanied by a toe drag during the swing phase. A knee flexion contracture or spasticity may cause the same alteration. Similarly, if the quadriceps are weak, the patient may extend the knee by using the hand or may hit the heel hard on the ground to whip the knee into extension. If heel pain occurs at initial contact, this pain may cause increased flexion of the knee, with early plantarflexion to relieve the stress or pressure on the painful tissues. 90

The ankle is usually within a few degrees of the neutral position at the time of initial contact, with the heel slightly inverted and the subtalar joint slightly supinated. 91The initial impact is taken through the lateral tubercle of the calcaneus, a structure unique to humans and designed to tolerate the shock of heel strike via the calcaneal fat pad. As the heel contacts the ground, its forward momentum comes to an abrupt halt. During the loading response interval, plantar flexion occurs at the talocrural joint, with pronation occurring at the subtalar joint. 91The pronation of the subtalar joint unlocks the foot and allows maximal range of motion of the midtarsal joint, which brings the articulating surfaces of the cuboid and navicular to a position relatively parallel to the weight-bearing surface and allows the forefoot to become supple. 92, 93This increase in midtarsal joint mobility enhances the foot's ability to adapt to the support surface. Abnormal responses during this interval include excessive or no knee motion as a result of weak quadriceps, plantar flexor contractures, or spasticity. 90

At the end of the midstance interval, the talocrural joint is maximally dorsiflexed, and the subtalar joint begins to supinate. During the latter part of the stance phase, the foot must become a rigid lever. However, if pain is elicited during this interval, the heel may lift off the floor early. From the midstance to the terminal stance interval, the foot is in supination. 92Supination at the subtalar joint locks the foot into a rigid lever 91, 94by promoting supination at the midtarsal joint, which results in the articulating surfaces of the cuboid and calcaneus adopting a position that is perpendicular to one another, thus stabilizing their articulation. 93The fixed cuboid acts as a fulcrum for the fibularis (peroneus) longus muscle, facilitating plantar flexion of the first metatarsal in pushing off. 92

Once the ankle is fully close packed, the heel is lifted by a combination of passive force and contraction from the taut gastrocnemius and the soleus. The lifting of the heel accentuates the force applied to the mid- and forefoot and reinforces the close packing of this area, while simultaneously unclose packing the ankle joint.

As ankle plantar flexion reaches its peak at the end of the terminal stance interval, the first metatarsophalangeal (MTP) joint is passively extended. This extension of the first MTP places tension on the plantar fascia and helps to elevate the medial longitudinal arch through the windlass mechanism of the plantar fascia (see Chapter 21). This windlass mechanism creates a dynamic stable arch and, hence, a more rigid lever for push off. 92However, if pain is elicited during this interval, the patient is unable to push off on the medial aspect of the foot and instead compensates by pushing off on the lateral aspect of the foot.

While the forefoot is on the ground and the heel is off, the heel is inverted and the foot is supinated. 91The plantar flexion action helps to smooth the pathway of the COG. The heel rise coincides with the opposite leg swinging by the stance leg. 95Approximately 40% of the body weight is borne by the toes in the final stages of foot contact. 96, 97Muscle activity during push off is designed to initiate propulsion. 92However, if the plantar flexors are weak, the push off may be absent.

From initial contact to early midstance, the tibia moves anteriorly, internally rotating within the ankle mortise, and producing talar adduction and plantar flexion, and calcaneal eversion (weight-bearing pronation of the subtalar joint). 92The forward tibial advancement requires approximately 10 degrees of ankle joint dorsiflexion to prevent excessive pronation at the subtalar and oblique midtarsal joints. 9, 93, 100

During the swing phase, the ankle must dorsiflex in order for the forefoot to clear the ground. However, if the ankle dorsiflexor muscles are weak, the patient must utilize a steppage gait, manifested by excessive flexion at the hip so that the toes can clear the ground. Prior to the next initial contact, the ankle adopts a neutral position in terms of dorsiflexion and plantar flexion.

Muscle Actions during Gait

During the swing phase, the semispinalis, rotatores, multifidus, and external oblique muscles are active on the side toward which the pelvis rotates. 4The erector spinae and internal oblique abdominal muscles are active on the opposite side. The psoas major and quadratus lumborum help to support the pelvis on the side of the swinging limb while the contralateral hip abductors also provide support.

The ankle and hip muscles are responsible for the majority of positive work performed during walking (54% of the hip and 36% of the ankle). 101The knee contributes the majority of the negative work (56%). 101The muscle actions that occur during the stance phase of gait are depicted in Table 6-3. 102

Hip

During the early to midportion of the swing phase, the iliopsoas is the prime mover, with assistance from the rectus femoris, sartorius, gracilis, adductor longus, and possibly the tensor fascia latae, pectineus, and short head of the biceps femoris during the initial swing interval. 4Perry notes the adductor longus muscle to be “the first and most persistent hip flexor.” 40In terminal swing, there is no appreciable action of the hip flexors when ambulating on level ground. Instead, the hamstrings and gluteus maximus are strongly active to decelerate hip flexion and knee extension. 33, 79Both these superficial muscles and their deeper counterparts, such as the hip adductors, gemelli, and short rotators, certainly contribute. 44In rapid walking, there is increased activity of the sartorius and the rectus femoris during the swing phase. 4

During initial contact, the gluteal muscles and the hamstrings contract isometrically with moderate intensity. The passive hip extension moment at initial contact has been calculated to be approximately 60–100% of the total moment occurring during the stance phase, suggesting that passive elastic energy is stored and released during gait. 103The loading response interval is accompanied by hamstring and gluteus maximus activity, which aids hip extension. 33, 79, 104The adductor magnus muscle supports hip extension and also rotates the pelvis externally toward the forward leg. In midstance, coronal plane muscle activity is greatest, as the abductors stabilize the pelvis. 105– 109The muscle activity initially is eccentric, as the pelvis shifts laterally over the stance leg.

The gluteus medius and minimus remain active in terminal stance for lateral pelvic stabilization. The iliacus and anterior fibers of the tensor fasciae latae are also active in the terminal stance and preswing intervals. 33, 79Notable, but inconsistent, muscle activity of the rectus femoris is described by several authors. 33, 79, 104The only muscles of the hip that contract significantly during the last part of the stance phase are the adductor magnus, longus, and possibly brevis. 4

Knee

The functions of the knee during gait are to absorb shock, reduce vertical displacement of the COG, maintain the stride length, bear weight, and allow the foot to move through its swing. During the swing phase, there is very little activity from the knee flexors. The knee extensors contract slightly at the end of the swing phase prior to initial contact. During level walking, the quadriceps achieve peak activity during the loading response interval (25% maximum voluntary contraction) and are relatively inactive by midstance as the leg reaches the vertical position and locks, making quadriceps contraction unnecessary. 39, 110– 112In graded exercise, Brandell 113examined the effect of speed and grade on electromyographic (EMG) activity of the quadriceps and calf musculature. The author concluded that increases in speed and grade resulted in a relative increase in EMG activity of the quadriceps compared with the calf musculature. Recently Ciccotti and colleagues 114noted similar magnitudes and profiles of EMG activity in the quadriceps during level walking (1.5 m/s) and ascending a ramp of 10% grade at the same speed as level walking. Although minimal data were presented for comparison, the authors did note a decrease in vastus lateralis activity from 16% to less than 10% of maximum manual muscle test, with the addition of a grade. Therefore, it remains questionable whether graded walking actually facilitates quadriceps activity. 69

Hamstring involvement is also important to normal knee function. The hamstrings provide dynamic stability to the knee by resisting both mediolateral and anterior translational forces on the tibia. 35The coactivation of the antagonist muscles about the knee during the loading response aids the ligaments in maintaining joint stability by equalizing the articular surface pressure distribution and controlling tibial translation. 115, 116EMG activity of the hamstrings during level walking has shown that the hamstrings decelerate the leg prior to heel contact and then act synergistically with the quadriceps during the stance phase to stabilize the knee. 111, 117The hamstrings also demonstrate activity at the end of the stance phase. Hamstring activity during graded walking and increased speed demonstrates increased activity and for a longer duration. 4

Foot and Ankle

During the beginning of the swing phase, the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and possibly the fibularis (peroneus) tertius contract concentrically with slight-to-moderate intensity, tapering off during the middle of the swing phase. 4, 118, 119As the swing phase begins, the fibularis (peroneus) longus also contracts concentrically to evert the entire foot and bring the sole of the foot parallel with the substrate. At the point where the leg is perpendicular to the ground during the swing phase, the tibialis anterior, extensor digitorum longus, and extensor hallucis longus group of muscles contract concentrically to dorsiflex and invert the foot in preparation for the initial contact. 4, 118, 119There is very little activity, if any, from the plantar flexors during the swing phase.

Following initial contact, the anterior tibialis works eccentrically to lower the foot to the ground during the loading response interval. 118, 119Loss of this plantar flexion control can result in an inability to transfer weight to the anterior foot, increased ankle dorsiflexion, and increased knee flexion. Calcaneal eversion is controlled by the eccentric activity of the posterior tibialis, and the anterior movement of the tibia and talus is limited by the eccentric action of the gastrocnemius and soleus muscle groups as the foot moves toward midstance. 102Pronation occurs in the stance phase to allow for shock absorption, ground terrain changes, and equilibrium. 93, 120The triceps surae become active again from midstance to the late stance phase, contracting eccentrically to control ankle dorsiflexion, as the COG continues to move forward. In late stance phase, the Achilles tendon is stretched, as the triceps surae contracts and the ankle dorsiflexes. 121At this point, the heel rises off the ground, and the action of the plantar flexors changes from one of eccentric contraction to one of concentric contraction. The energy stored in the stretched tendon helps to initiate plantar flexion and the initiation of propulsion. 121The fibularis (peroneus) longus provides important stability to the forefoot during propulsion.

The clinical examination of gait can be performed using methods ranging from observation to computerized analysis ( Table 6-4). Computerized gait analysis measures gait parameters more precisely than is possible with clinical observation alone, 122, 123and it is used in the evaluation and treatment planning for patients with gait abnormalities. 124However, computerized gait analysis is often cost prohibitive and, thus, not practical for most clinicians, who must therefore rely on their powers of observation. The reliability and agreement both between and within raters for gait problems detected by observation alone has been reported. Krebs and colleagues 123found moderate reliability within and between physical therapists observing children's gait from videotape. Eastlack and associates 125found only slight to moderate reliability between raters in the assessment of deviations at a single joint from a videotape. 124

Perhaps, the most commonly used gait analysis chart is the one designed by the Rancho Los Amigos Medical Center ( Fig. 6-5), which allows the clinician to determine deviations and their effect on gait in a user-friendly format.

Several other examination tools are available. Some of these tools are specific to a particular population. For example, the modified version of the Gait Abnormality Rating Scale ( Table 6-5) can be used with community-dwelling frail older persons to help predict individuals who are at high risk for falling. 126

Dysfunction of the vestibular system may lead to gait abnormalities. 127, 128The Functional Gait Assessment ( Table 6-6) is a 10-item test that comprises seven of the eight items from a previous test called the Dynamic Gait Index, which was developed to assess postural stability during gait tasks in the older adult (greater than 60 years of age) at risk for falling. 129According to the designers of the Functional Gait Assessment, the tool demonstrates acceptable reliability, internal consistency, and concurrent validity with other balance measures used for patients with vestibular disorders. 128Intervention strategies for vestibular dysfunction are described in Chapter 14.

Observational Analysis

Observational analysis of gait should focus on one gait interval at a time. For example, the clinician should observe the pattern of initial contact with the floor and then, in turn, study the actions throughout the initial contact at the ankle, knee, hip, pelvis, trunk, and upper extremities.

A paper walkway, approximately 25-ft long, on which the patient's footprints can be recorded, is very useful for gait analysis. 41, 130To assess gait, knowledge of what is deemed abnormal and the reasons for those abnormalities are prerequisite ( Table 6-7).

Gait is assessed by having the patient walk barefoot and with footwear. Barefoot walking provides information about foot function without support and can highlight compensations, such as excessive pronation and foot deformities, such as claw toes. 131Having the patient walk with footwear can provide information about the effectiveness of the footwear to counteract the compensations. The patient should be asked to walk on the toes and then on the heels. An inability to perform either of these actions could be the result of pain, weakness, or a motion restriction, or a combination of all. Metatarsalgia is indicated if the metatarsal heads are made more painful with barefoot walking. Pain at initial contact may indicate a heel spur, bone contusion, calcaneal fat padinjury, or bursitis.

The patient's footwear is examined for patterns of wear. The greatest amount of wear on the sole of the shoe should occur beneath the ball of the foot and in the area corresponding to the first, second, and third MTP joints, and slight wear to the lateral side of the heel. The upper portion of the shoe should demonstrate a transverse crease at the level of the MTP joints. A stiff first MTP joint can produce a crease line that runs obliquely, from forward and medial to backward and lateral. 132Scuffing of the top of the shoe at its front might indicate tibialis anterior weakness or adaptively shortened heel cords. 131

The patient's foot is also examined for callus formation, blisters, corns, and bunions. Callus formation on the sole of the foot is an indicator of dysfunction and provides the clinician with an index to the degree of shear stresses applied to the foot, and a clear outline of abnormal weight-bearing areas. 133Adequate amounts of calluses may provide protection, but in excess amounts they may cause pain. Callus formation under the second and third metatarsal heads could indicate excessive pronation in a flexible foot, or Morton neuroma, if just under the former. A callus under the fifth, and sometimes the fourth, metatarsal head may indicate an abnormally rigid foot.

The patient is asked to walk in his or her usual manner and at the usual speed. The clinician begins the gait assessment with an overall look at the patient while they walk and noting the cadence, stride length, step length, and velocity. The arm swing during gait should also be observed. If an individual has a problem with the foot or ankle on one side, the opposite arm swing is often decreased. 95

The patient is observed from head to toe and then back again, from the side, from the front, and then from the back.

In addition to observing the patient walking at his or her normal pace, the clinician should also observe the patient walking at varying speeds. This can be achieved on a treadmill by adjusting the speed or by asking the patient to change the walking speed.

Once an overall assessment has been made of the patient's gait, the clinician can focus attention on the various segments of the kinetic chain of gait, including the trunk, pelvis, lumbar spine, hip, knee, and ankle and foot.

Attempts are made to determine the primary cause of any gait deviations or compensations (see Table 6-7).

Anterior View

When observing the patient from the front, the clinician can note the following:

• Head position—the subject's head should not move too much during gait in a lateral or vertical direction and should remain fairly stationary during the gait cycle. A “bouncing” gait is characteristic of adaptively shortened gastrocnemii or increased tone of the gastrocnemius and soleus.
• Amount of lateral tilt of the pelvis.
• Amount of lateral displacement of the trunk and pelvis.
• Whether there is excessive swaying of the trunk or pelvis.
• Amount of vertical displacement—vertical displacement can be assessed by observing the patient's head.
• Reciprocal arm swing—movements of the upper trunk and limbs usually occur in the opposite direction to the pelvis and the lower limbs.
• Whether the shoulders are depressed, retracted, or elevated.
• Whether the elbows are flexed or extended.
• Amount of hip adduction or abduction that occurs. Causes of excessive adduction include an excessive angle of the coxa vara, hip abductor weakness, hip adductor contracture or spasticity, and contralateral hip abduction contracture. Excessive hip abduction may be caused by an abduction contracture, a short leg, obesity, impaired balance, or hip flexor weakness. 134
• Amount of valgus or varus at the knee—during gait, there may be an obvious varus-extension thrust. According to Noyes and colleagues, this gait pattern is characteristic of chronic injuries to the posterolateral structures of the knee. 135
• Width of the BOS, or step width.
• Degree of “toe-out”—the term toe-outrefers to the angle formed by the intersection of the line of progression of the foot and the line extending from the center of the heel through the second metatarsal. The normal toe-out angle is approximately 7 degrees, and this angle decreases as the speed of gait increases. 30
• Whether any circumduction of the hip occurs. Hip circumduction can indicate a leg-length discrepancy, decreased ability of the knee to flex, or hip abductor shortening or overuse.
• Whether any hip hiking occurs. Hip hiking can indicate a leg-length discrepancy, hamstring weakness, or shortening of the quadratus lumborum.
• Evidence of thigh atrophy.
• Degree of rotation of the whole lower extremity. Because positioning the lower extremity in external rotation decreases the stress on the subtalar joint complex, an individual with a foot or ankle problem often adopts this position during gait. 95Excessive internal or external rotation of the femur can indicate adaptive shortening of the medial or lateral hamstrings, respectively, resulting in anteversion or retroversion, respectively.

Lateral View

When observing the patient from the side, the clinician can note the following:

• Amount of thoracic and shoulder rotation. Each shoulder and arm should swing reciprocally, with equal motion.
• Orientation of trunk. The trunk should remain erect and level during the gait cycle, as it moves in the opposite direction to the pelvis. Compensation can occur in the lumbar spine for a loss of motion at the hip. A backward lean of the trunk may result from weak hip extensors or inadequate hip flexion. A forward lean of the trunk may result from pathology of the hip, knee, or ankle; abdominal muscle weakness; decreased spinal mobility; or hip flexion contracture. Forward leaning during the loading response and early midstance intervals may indicate hip extensor weakness. 136
• Orientation of the pelvic tilt. An anterior pelvic tilt of >10 degrees is considered normal. Excessive anterior tilting can be caused by weak hip extensors, hip flexion contracture, or hip flexor spasticity. Excessive posterior pelvic tilting during gait usually occurs in the presence of hip flexor weakness.
• Degree of hip extension. Causes of inadequate hip extension and excessive hip flexion include hip flexion contracture, iliotibial band contracture, hip flexor spasticity, or pain. 134Causes of inadequate hip flexion may include hip flexor weakness or hip joint arthrodesis. 134
• Knee flexion and extension. The knee should be extended during the initial contact interval, followed by slight flexion during the loading response interval. During the swing phase, there must be sufficient knee flexion. Causes of excessive knee flexion and inadequate knee extension include inappropriate hamstring activity, knee flexion contracture, soleus weakness, and excessive ankle plantar flexion. Causes of inadequate flexion and excessive extension at the knee include quadriceps weakness, pain, quadriceps spasticity, excessive ankle plantar flexion, hip flexor weakness, and knee extension contractures. 137Individuals with genu recurvatum may have a functional strength deficit in the quadriceps muscle or gastrocnemius that allows knee hyperextension. 138
• Ankle dorsiflexion and plantar flexion. During midstance, the ankle dorsiflexes and the body pivots over the stationary foot. At the end of the stance phase, the ankle should be seen to plantar flex to raise the heel. At the beginning of the swing phase, the ankle is plantar flexed, moving into dorsiflexion as the swing phase progresses and reaches a neutral position at the time of heel contact at the termination of the swing. Excessive plantar flexion in midswing, initial contact, and loading response may be caused by pretibial (especially the anterior tibialis) weakness. Excessive plantar flexion also may be caused by plantar flexion contracture, soleus and gastrocnemius spasticity, or weak quadriceps. 90Excessive dorsiflexion may be caused by soleus weakness, ankle fusion, or persistent knee flexion during the midstance phase. 136
• Stride length of each limb.
• Cadence. The cadence should be normal for the patient's age ( Table 6-7).
• Heel rise. An early heel rise indicates an adaptively shortened Achilles tendon. 95Delayed heel rise may indicate a weak gastrocnemius–soleus complex.
• Heel contact. A low heel contact during initial contact may be caused by plantar flexion contracture, tibialis anterior weakness, or premature action by the calf muscles. 90
• Preswing. An exaggerated preswing is manifested by the patient walking on the toes. Causes include pes equines deformity, adaptive shortening or increased tone of the triceps surae, weakness of the dorsiflexors, and knee flexion occurring at midstance. A decreased preswing is often characterized by a lack of plantar flexion at terminal stance and preswing. Causes for this can include ankle or foot pain or weakness of the plantar flexor muscles.

Posterior View

When observing the patient from the back, the clinician can note the following:

• Amount of subtalar inversion (varus) or eversion (valgus). Excessive inversion and eversion usually relate to abnormal muscular control. Generally speaking, varus tends to be the dominant dysfunction in spastic patients, whereas valgus tends to be more common with flaccid paralysis. 90
• BOS/step width.
• Pelvic list.
• Degree of hip rotation—as in standing, excessive femoral internal rotation past the midstance of gait will accentuate genu recurvatum. Causes of excessive external hip rotation may include gluteus maximus overactivity and excessive ankle plantar flexion. 134Causes of excessive internal hip rotation include medial hamstring overactivity, hip adductor overactivity, anterior abductor overactivity, and quadriceps weakness. 134
• Amount of hip adduction or abduction.
• Amount of knee/tibial rotation.

Each of the attributes of normal gait described earlier under “Characteristics of Normal Gait”are subject to compromise by disease states, particularly neuromuscular conditions. 101In general, gait deviations fall under four headings: those caused by weakness, those caused by abnormal joint position or range of motion, those caused by muscle contracture, and those caused by pain. 22, 139

• Weakness implies that there is inadequate internal joint movement or loss of the natural force–couple relationship.
• Neuromuscular conditions may be associated with abnormalities of muscle tone, timing of muscle contractions, and proprioceptive and sensory disturbances, the latter of which can profoundly affect reflex postural balance.
• Abnormal joint position can be caused by an imbalance of flexibility and strength around a joint or by contracture.
• Contractures, changes in the connective tissue of muscles, ligaments, and the joint capsule, may produce changes in gait. If the contracture is elastic, the gait changes are apparent in the swing phase only. If the contractures are rigid, the gait changes are apparent during the swing and the stance phases.
• Pain can alter gait, as the patient attempts to use the position of minimal articular pressure (see “Antalgic Gait”). Pain may also produce muscle inhibition and eventual atrophy.

Antalgic Gait

The antalgic gait is characterized by a decrease in the stance phase on the involved side in an attempt to eliminate the weight from the involved leg and use of the injured body part as much as possible. The antalgic gait pattern can result from numerous causes ( Table 6-8), including disease, joint inflammation ( Table 6-9), or an injury to the muscles, tendons, and ligaments of the lower extremity. In the case of joint inflammation, attempts may be made to avoid positions of maximal intraarticular pressure and to seek the position of minimum articular pressure 140:

• Minimum articular pressure occurs at the ankle at 15 degrees of plantar flexion.
• Minimum articular pressure occurs at the knee at 30 degrees of flexion. With a painful knee, the gait is characterized by a decrease in knee flexion at initial contact and the loading response interval, and an increase in knee extension during the remainder of the stance phase.
• Minimum articular pressure occurs at the hip at 30 degrees of flexion.

Perhaps surprisingly, recent studies have shown that the gait pattern is altered in individuals with low back pain. 141These individuals exhibit a cautious gait exemplified by a reduction in cycle duration as well as hip flexion–extension excursion. 142When compared to healthy controls, patients with back pain exhibit similar patterns of activation across the gait cycle, but with premature activity in the lumbar spine and hip extensor muscles, and prolonged activity of the gluteus maximus and spine extensors. 141This raises the question as to what role the CNS plays in this alteration of gait. 143

Equinus Gait

Spastic diplegia is the most common pattern of motor impairment in patients with cerebral palsy. 144In these patients, motor impairment occurs as a result of a number of deficits, including poor muscle control, weakness, impaired balance, hypertonicity, and spasticity. 145However, reduced joint motion as a consequence of spasticity is perhaps the most noticeable and recorded impairment. As a consequence, muscle–tendon units frequently become contracted over time, contributing to malalignment of the extremity during gait.

Equinus gait (toe-walking), one of the more common abnormal patterns of gait in patients with spastic diplegia (see also “Spastic Gait”), is characterized by forefoot strike to initiate the cycle and premature plantar flexion in early to midstance. 146Toe-walking may be a primary gait deviation, which is the consequence of excessive myostatic contracture of the triceps surae, excessive dynamic contraction of the ankle plantar flexors, or a combination of both factors. Additionally, toe-walking may be a compensatory deviation for myostatic deformity or dynamic overactivity of the ipsilateral hamstring muscles, which directly limits knee alignment and secondarily compromises foot and ankle position during stance phase.

Associated gait deviations are frequently seen at the knees, hips, and pelvis in children with cerebral palsy who are walking on their toes 147:

• Deviations seen at the knees include increased flexion in stance phase at initial contact and in midstance, and delayed and diminished peak knee flexion in swing phase.
• The hips often show diminished extension in the sagittal plane at terminal stance.
• A common deviation seen at the pelvis in children with cerebral palsy who are toe-walking is an increased anterior tilt.

Gluteus Maximus Gait

The gluteus maximus gait, which results from weakness of the gluteus maximus, is characterized by a posterior thrusting of the trunk at initial contact in an attempt to maintain hip extension of the stance leg. The hip extensor weakness also results in an anterior tilt of the pelvis, which eventually translates into hyperlordosis of the spine to maintain posture.

Quadriceps Gait

Quadriceps weakness can result from a peripheral nerve lesion (femoral), spinal nerve root lesion (L2–4), trauma, or disease (muscular dystrophy). Although often appearing to have a normal gait pattern when walking on a level surface, the patient with quadriceps weakness/paralysis often demonstrates difficulty walking on rough or inclined surfaces and stairs and is unable to run. In such instances forward motion is propagated by circumducting each leg. To compensate, the patient leans the body toward the uninvolved side to balance the COG and swings the involved leg like a pendulum.

Steppage Gait

This type of gait occurs in patients with a foot drop. A foot drop is the result of weakness or paralysis of the dorsiflexor muscles resulting from an injury to the muscles, their peripheral nerve supply, or the nerve roots supplying the muscles ( Table 6-10). 148The patient lifts the leg high enough to clear the flail foot off the floor, by flexing excessively at the hip and knee, and then slaps the foot on the floor.

Trendelenburg Gait

This type of gait results from weakness of the hip abductors (gluteus medius and minimus). The normal stabilizing effect of these muscles is lost, and the patient demonstrates an excessive lateral list, in which the trunk is thrust laterally in an attempt to keep the COG over the stance leg. A positive Trendelenburg sign is also present ( Table 6-10).

Plantar Flexor Gait

This type of gait is characterized by walking on the toes ( Table 6-10). The plantar flexor gait demonstrates premature firing of the calf muscle in the swing phase of gait with EMG. 149A toe-walking gait pattern describes dynamic ankle deviations that include 147

• a loss of heel strike at initial contact, with disruption of the first ankle rocker;
• disruption of the second rocker, with ankle plantar flexion (instead of dorsiflexion) occurring at midstance;
• variable disruption of the third rocker in terminal stance;
• variable ankle alignment during swing phase.

This is a common gait deviation in children with cerebral palsy. For the clinician, the challenge is to distinguish between changes that are the direct consequence of such an underlying neuromuscular disorder and are, therefore, primary, and those changes that result from biomechanical constraints of toe-walking and are, therefore, secondary or compensatory. It is not unusual for normal children to display intermittent tiptoe gait when they first begin to walk; however, a more mature heel-toe gait pattern should become consistent by the age of 2 years. 150Older children with persistent tiptoe gait are often labeled idiopathic toe walkers. Toe-walking that begins after a mature heel-toe gait pattern has been established may signify muscular dystrophy, diastematomyelia, peroneal muscular atrophy, or spinal cord tumor. Toe-walking has been associated with premature birth, developmental delay, schizophrenia, autism, and various learning disorders. 151

Spastic Gait

A spastic gait may result from either unilateral or bilateral upper motor neuron lesions. A number of types are recognized.

Spastic Hemiplegic (Hemiparetic) Gait

This type of gait results from a unilateral upper motor neuron (UMN) lesion. Spastic hemiplegic gait is frequently seen following a completed stroke. Spasticity of all muscles on the involved side is noted, but it is more marked in some muscle groups. During gait, the leg tends to circumduct in a semicircle, rotating outward, or is pushed ahead, with the foot dragging and scraping the floor. The upper limb typically is carried across the trunk for balance ( Table 6-11).

Spastic Paraparetic Gait

This type of gait results from bilateral UMN lesions (e.g., cervical myelopathy in adults and cerebral palsy in children). Spastic paraparetic gait is characterized by slow, stiff, and jerky movements. Spastic extension occurs at the knees, with adduction at the hips (scissors gait).

Ataxic Gait

The ataxic gait is seen in two principal disorders: cerebellar disease (cerebellar ataxic gait) and posterior column disease (sensory ataxic gait) ( Table 6-11).

Cerebellar Ataxic Gait

The nature of the gait abnormality with a cerebellar lesion is determined by the site of the lesion. In vermal lesions, the gait is broad based, unsteady, and staggering, with an irregular sway. The patient is unable to walk in tandem or in a straight line. The ataxia of gait worsens when the patient attempts to stop suddenly or to turn sharply, resulting in a tendency to fall.

In hemispheral lesions, the ataxia tends to be less severe, but there is persistent lurching or deviation toward the involved side.

Sensory Ataxic Gait

With this type of ataxia, because the patient is unaware of the position of the limbs, the gait is broad based, and the patient tends to lift the feet too high and slap on the floor in an uncoordinated and abrupt manner. The patient tends to watch the floor and the feet to maximize attempts at visual correction and may have difficulty walking in the dark.

Parkinsonian Gait

The Parkinsonian gait is characterized by a flexed and stooped posture, with flexion of the neck, elbows, metacarpophalangeal joints, trunk, hips, and knees ( Table 6-11). The patient has difficulty initiating movements and walks using short steps, with the feet barely clearing the ground. This results in a shuffling type of gait with rapid steps. As the patient gets going, he or she may lean forward and walk progressively faster, as though chasing the COG (propulsive or festinating gait). Less commonly, deviation of the COG backward may cause retropulsion. There is also a lack of associated arm movement during the gait, because the arms are held stiffly.

Hysterical Gait

The hysterical gait is nonspecific and bizarre. It does not conform to any specific organic pattern, with the abnormality varying from moment to moment and from one examination to another. There may be ataxia, spasticity, inability to move, or other types of abnormality. The abnormality is often minimal or absent when the patient is unaware of being watched or when distracted. However, although all hysterical gaits are bizarre, all bizarre gaits are not hysterical.

Pregnancy

Substantial hormonal and anatomic changes occur during pregnancy, which dramatically alter body mass, body mass distribution, and joint laxity. During pregnancy, musculoskeletal disorders are common and may cause problems ranging from mild discomfort to serious disability. It is widely presumed that pregnant women exhibit marked gait deviations. The results of a recent study appear to refute that notion. 152The study concluded that velocity, stride length, and cadence during the third trimester of pregnancy were similar to those measured 1 year postpartum and that only small deviations in pelvic tilt and hip flexion, extension, and adduction were observed during pregnancy. 152The study found significant increases ( p< 0.05) in hip extensor, hip abductor, and ankle plantar flexor kinetic gait parameters, which suggests an increased use of hip extensor, hip abductor, and ankle plantar flexor muscles to compensate for increases in body mass and changes in body mass distribution during pregnancy. These increases keep speed, stride length, cadence, and joint angles relatively unchanged. 152However, these compensations may result in overuse injuries to the muscle groups about the pelvis, hip, and ankle, including low back, pelvic, and hip pain; calf cramps; and other painful lower extremity musculoskeletal conditions associated with pregnancy. 152It was unclear from this study whether the women examined had gained normal amounts of weight associated with pregnancy. It would seem obvious that obesity associated with pregnancy may have differing affects on gait.

Obesity

As obesity is reaching epidemic proportions in the United States and is a growing problem in developed countries, the clinician needs to be aware of its effects on the normal gait pattern to help discriminate compensatory patterns as opposed to pathologic manifestations. Obesity is associated with a number of comorbidities, such as coronary artery disease, type 2 diabetes, gall bladder disease, and sleep apnea. Given a normal body mass index (defined as the weight in kilograms divided by the square of the height in meters) ranging from 18.5 to 24.9, 34% of the adult population is overweight (body mass index of 25–29.9) and another 27% is obese (body mass index of 30 or more). 153

The gait used by the obese patient is often described as a waddling gait. Depending on the degree of obesity, the waddling gait is characterized by increased lateral displacement, pelvic obliquity, hip circumduction, increased knee valgus, external foot progression angle, overpronation, and increases in the normalized dynamic BOS. Nantel and colleagues 154compared the biomechanical parameters between obese and nonobese children during self-paced walking. Kinematics were captured with eight VICON optoelectronic cameras (Oxford Metrics Limited, Oxford, UK) recording at 60 Hz. Findings from the study revealed that obese children modified their hip motor pattern by shifting from extensor to flexor moment earlier in the gait cycle. This led obese children to significantly decrease the mechanical work done by the hip extensors during weight acceptance and significantly increase the mechanical work done by the hip flexors, compared with nonobese children. Finally, there was a significant decrease in the single support duration in the obese group compared with nonobese. Gushue and colleagues 155attempted to quantify the three-dimensional knee joint kinematics and kinetics during walking in children of varying body mass and to identify effects associated with obesity. The study found that the overweight group walked with a significantly lower peak knee flexion angle during early stance, and no significant differences in peak internal knee extension moments were found between groups. However, the overweight group showed a significantly higher peak internal knee abduction moment during early stance. These data suggest that although overweight children may develop a gait adaptation to maintain a similar knee extensor load, they may not be able to compensate for alterations in the frontal plane, which may lead to increased medial compartment joint loads. 155Finally, in a study by de Souza and colleagues, 156an outpatient population (age 47.2 ± 12.9 years, 94.1% females, BMI 40.1 ± 6.0 kg/m 2, n= 34) had their gait analyzed by an experienced physical therapist. Variables included speed, cadence, stride, step width, and foot angle, which were compared to reference values. All variables were significantly lower in the obese patients, except for step width, which was increased. Speed was 73.3 ± 16.3 vs. 130 cm/s, cadence was 1.4 ± 0.2 vs. 1.8 steps/s, stride was 106.8 ± 13.1 vs. 132.0 cm, and step width was 12.5 ± 3.5 vs. 10.0 cm ( p< 0.05). The authors concluded that these findings were consistent with poor skeletal muscle performance, high metabolic expenditure, and constant physical exhaustion. 156

Obesity also impacts other areas of mobility such as sit to stand transfers. In obese adults, sit to stand is performed by placing the feet further under the body and utilizing less hip flexion than in the nonobese. 143While this results in a decrease torque at the hip, it also results in an increase torque demand and joint stress at the knee. 158Perhaps more alarmingly is the finding that obese children have significant difficulty with the sit to stand task. 143In one study, 69% of obese children required assistance to perform a sit to stand transfer. 159

Although the functional comorbidities of excess body weight such as gait problems are perhaps clinically insignificant compared to those associated with certain metabolic sequelae, they may interfere with the quality of life and also act to increase muscle, bone, and joint stress. For example, the changes in the natural alignment of the weight-bearing segments may result in overuse injuries such as tendonitis and bursitis and eventual osteoarthritis of the hip or knee, or both.

Individuals undergoing knee replacement and hip replacement surgery demonstrate impaired gait patterns: 143

• Knee replacement.The gait tends to present with slower preoperative and postoperative cadence than age-matched normals, as well as shorter step length both preoperatively and postoperatively. 160These changes remain stable for 1–2 years after surgery. 160Individuals with knee replacement surgery also continue to exhibit reduced knee excursion during gait before and after surgery at all time points. 160Muscle activation also remains altered with a stiff knee gait pattern that involves coactivation during the stance phase predominating up to 2 years postoperatively. 161
• Hip replacement.Individuals undergoing both the posterolateral and the anterolateral surgical approaches have demonstrated altered gait parameters at 6 months postoperative. 162The anterolateral approach tends to lead to greater trunk forward inclination and a Trendelenburg gait pattern, whereas the posterolateral approach has a greater incidence of dislocation. 162

The most common cause for the breakdown of the normal gait cycle is an injury to one or both of the lower extremities. Such an injury usually results in an antalgic gait. If the injury is severe enough, an assistive device is needed. Assistive devices are used to make ambulation as safe and as painless as possible. However, it must be remembered that there is an energy cost associated with the use of assistive devices. Energy expenditure during walking with assistive devices such as crutches or a walker has generally been examined only in younger people with contrasting results. One study 163showed that walking with crutches resulted in lower VO2 compared with walking with a rollator or a standard walker. Compared with unassisted walking, walking with a wheeled walker resulted in more oxygenuse. Another study 164found that subjects 75 years of age or older, consumed an average of 2.8 METS when walking while using a wheeled walker; this corresponds to a moderate level of intensity according to the ACSM scale for the very old. 165– 167

In essence, an assistive device is an extension of the upper extremity, used to provide support, balance, and weight bearing normally provided by an intact functioning lower extremity. 168Assistive devices function to reduce ground reaction forces, with the size of the BOS that they provide being proportional to the amount of reduction in these forces.

Assistive devices, in order of the stability they provide, include a walker, crutches, walker cane, quad cane, straight cane, and bent cane, with the walker providing the most stability.

The indications for using an assistive device include 169

• decreased ability to bear weight through the lower extremities;
• muscle weakness or paralysis of the trunk or lower extremities;
• decreased balance and proprioception in the upright posture.

Correct fitting of an assistive device is important to ensure for the safety of the patient and to allow for minimal energy expenditure. Once fitted, the patient should be taught the correct walking technique with the device. The fitting depends on the device chosen:

• Walkers, hemiwalking canes, quad canes, and standard canes.The height of the device handle should be adjusted to the level of the greater trochanter of the patient's hip.
• Standard crutches.A number of methods can be used for determining the correct crutch length for axillary crutches. The crutch tip should be vertical to the ground and positioned approximately 15-cm (6 in.) lateral and 15-cm (6 in.) anterior to the patient's foot. The handgrips of the crutch are adjusted to the height of the greater trochanter of the hip of the patient. There should be a 5–8-cm (2–3 in.) gap between the top of the axillary pads and the patient's axilla. Bauer and colleagues 170found that the best calculation of ideal crutch length was either 77% of the patient's height or the height minus 40.6 cm (16 in.).
• Forearm/loftstrand crutches.The crutch is adjusted so that the handgrip is level with the greater trochanter of the patient's hip and the top of the forearm cuff just distal to the elbow.
• Canes.Using a cane to aid walking is perhaps as old as the history of humankind. In ancient times, canes were used for support, defense, and the procurement of food. 171Later, canes became a symbol of power and aristocracy. 172Currently, canes are used to provide support and protection, to reduce pain in the lower extremities, and to improve balance during ambulation. 173It is common practice to instruct patients with lower extremity pain to use the cane in the hand contralateral to the symptomatic side. 174The use of a cane in the contralateral hand helps preserve reciprocal motion and a more normal pathway for the COG. 175Use of a cane in this fashion also helps to decrease forces at the hip, as estimated by external kinematics and kinetics. 176– 179Use of a cane can transmit 20–25% of body weight away from the lower extremities. 180, 181The cane also allows the subject to increase the effective BOS, thereby decreasing the hip abductor force exerted.

The clinician must always provide adequate physical support and instruction while working with a patient using an assistive gait device. The clinician positions himself or herself on the involved side of the patient, to be able to assist the patient on the side where the patient will most likely have difficulty. In addition, a gait belt should be fitted around the patient's waist to enable the clinician to assist the patient. When ambulating with a patient, the clinician should be just behind the patient, standing toward the involved side.

The selection of the proper gait pattern to instruct the patient is dependent on the patient's balance, strength, cardiovascular status, coordination, functional needs, and weight-bearing status:

• NWB.Patient is not permitted to bear any weight through the injured limb.
• Partial weight-bearing (PWB).Patient is permitted to bear a portion (25%, 50%, etc.) of his or her weight through the injured limb.
• Touch down weight-bearing/toe touch weight-bearing.Patient is permitted minimal contact of the injured limb with the ground for balance. The expression “as though walking on eggshells” can be used to help the patient understand.
• Weight-bearing as tolerated.The patient is permitted to bear as much weight through the injured limb as is comfortable.
• Full weight-bearing.Patient no longer medically requires an assistive device.

Several gait patterns are recognized ( Table 6-12).

Sit‐to-Stand Transfers

Before the patient can begin ambulation, he or she must first learn to safely transfer from a sitting position to a standing position. The wheels of the bed or wheelchair are locked, and the patient is reminded of any weight-bearing restrictions. The patient is asked to slide to the front edge of the chair or bed, and the weight-bearing foot is placed underneath the body so that the COG is closer to the BOS, which will make it easier for the patient to stand.

The patient is then instructed to lean forward and push up with the hands from the bed or armrests.

• If the patient is being instructed on the use of a walker, he or she should grasp the handgrips of the walker only after becoming upright and should not be permitted to try to pull up to a standing position using the walker, because this can cause the walker to tip over and increase the potential for falls.
• If the patient is using crutches, he or she is instructed to hold both crutches with the hand on the same side as the involved lower extremity. The patient then presses down on the handgrips of the crutches, the armrest, or bed and with the uninvolved lower extremity, to stand. Once standing, and with adequate balance, the patient moves the crutches into position and begins to ambulate.
• If the patient is using one or two canes, he or she is instructed to push up with the hands from the bed or armrests. Once standing, the patient should grasp the handgrip(s) of the cane(s) with the appropriate hand and begin to ambulate.

Stand‐to-Sit Transfers

The stand-to-sit transfer is essentially the reverse of the sit-to-stand transfer. In order to sit down using an assistive device, the patient must first back up against the front edge of the bed or chair. If the patient has difficulty bending the knee of the involved lower extremity, he or she is instructed to slowly advance this extremity forward. Once in position

• the patient using a walker reaches for the bed or armrest with both hands and slowly sits down;
• the patient using crutches moves both crutches to the hand on the side of the involved lower extremity. With that hand holding onto both handgrips of the crutches, the patient reaches back for the bed or armrest with the other hand before slowly sitting down;
• The patient using one or two canes places the handgrip of the cane(s) against the edge of the chair or bed. Next, the patient reaches back for the bed or armrest and slowly sits down.

Stair Negotiation

Ascending Stairs

To ascend steps, the patient must first move to the front edge of the step. The walker will have to be turned toward the opposite side of the handrail or wall. Ascending more than two to three stairs with a walker is not recommended.

• To ascend stairs using a walker, the patient is instructed to grasp the stair handrail with one hand and to turn the walker sideways so that the two front legs of the walker are placed on the first step. When ready, the patient pushes down on the walker handgrip and the handrail and advances the uninvolved lower extremity onto the first step. The patient then advances the uninvolved lower extremity to the first step and moves the legs of the walker to the next step. This process is repeated as the patient moves up the steps.
• To ascend steps or stairs with crutches, the patient should grasp the stair handrail with one hand and grasp both crutches by the handgrips with the other hand. If the patient is unable to grasp both crutches with one hand, or if the handrail is not stable, then the patient should use both crutches only, although this is not recommended if there are more than two to three steps. When in the correct position at the front edge of the step, the patient pushes down on the crutches and handrail, if applicable, and advances the uninvolved lower extremity to the first step. The patient then advances the involved lower extremity and finally the crutches. This process is repeated for the remaining steps.
• To ascend steps or stairs with one or two canes, the patient should use the handrail and the cane(s). If the handrail is not stable, then the patient should use the cane(s) only. The patient pushes down on the cane(s) or handrail, if applicable, and advances the uninvolved lower extremity to the first step. The patient then advances the involved lower extremity. This process is repeated for the remaining steps.

Descending Stairs

In order to descend steps, the patient must first move to the front edge of the top step. Descending more than two to three stairs with a walker is not recommended.

• To descend stairs using a walker, the walker is turned sideways so that the two front legs of the walker are placed on the lower step. One hand is placed on the rear handgrip, and the other hand grasps the stair handrail. When ready, the patient lowers the involved lower extremity down to the first step. Then the patient pushes down on the walker and handrail and advances the uninvolved lower extremity down the first step. This process is repeated as the patient moves down the steps.
• To descend steps or stairs with crutches, the patient should use one hand to grasp the stair handrail and the other to grasp both crutches and handrail. If the patient is unable to grasp both crutches with one hand, or if the handrail is not stable, then the patient should use both crutches only, although this is not recommended if there are more than two to three steps. When ready, the patient lowers the involved lower extremity down to the first step. Next, the patient pushes down on the crutches and handrail, if applicable, and advances the uninvolved lower extremity down to the first step. This process is repeated for the remaining steps.
• To descend steps or stairs with one or two canes, the patient should use the cane(s) and handrail. If the handrail is not stable, then the patient should use the cane(s) only. When ready, the patient lowers the involved lower extremity down to the first step. Next, the patient pushes down on the cane(s) and handrail, if applicable, and advances the uninvolved lower extremity down to the first step. This process is repeated for the remaining steps.

Instructions

Whichever gait pattern is chosen, it is important that the patient receive verbal and illustrated instructions for use of the assistive gait device to negotiate stairs, curbs, ramps, doors, and transfers. These instructions should include any weight-bearing precautions pertinent to the patient, the appropriate gait sequence, and a contact number at which to reach the clinician if questions arise.

As with the so-called good movement, good postureis a subjective term reflecting what the clinician believes to be correct based on ideal models. Various attempts have been made to define and interpret posture. 79, 182– 185Good posture may be defined as “the optimal alignment of the patient's body that allows the neuromuscular system to perform actions requiring the least amount of energy to achieve the desired effect.” 184Postural or skeletal alignment has important consequences as each joint has a direct effect on both its neighboring joint and on the joints further away. A syndrome is a characteristic pattern of symptoms or dysfunctions. Abnormal or nonneutralalignment is defined as “positioning that deviates from the midrange position of function.” 186To be classified as abnormal or dysfunctional, the alignment must produce physical functional limitations. These functional limitations can occur anywhere along the kinetic chain, at adjacent or distal joints through compensatory motions or postures.

The overall contour of the normal vertebral column in the coronal plane is straight. In contrast, the contour of the sagittal plane changes with development. At birth, a series of primary curves give a kyphotic posture to the whole spine. With development of the erect posture, secondary curves develop. For example, the cervical spine forms a lordotic curve that develops secondary to the response of an upright posture, which initially occurs when the child begins to lift the head at 3–4 months. The presence of the curve allows the head and eyes to remain oriented forward and provides a shock-absorbing mechanism to counteract the axial compressive force produced by the weight of the head. 35The curves in the spinal column provide it with increased flexibility and shock-absorbing capabilities. 187

Postural alignment is both static and dynamic. The postural control system, the mechanism by which the body maintains balance and equilibrium, has been divided into several subsystems, namely, the vestibular, visual, and somatosensory subsystems (see Chapter 3). 188, 189In a multisegmented organism such as the human body, many postures are adopted throughout the course of a day. Nonneutral alignment, whether maintained statically, or performed repetitively, appears to be a key precipitating factor in soft tissue and neurologic pain. 190This may be the result of an alteration in joint load distribution or in the force transmission of the muscles. This alteration can result in a muscle imbalance.

The ability to maintain correct posture appears to be related to a number of factors: 191, 192

• Energy cost.192The increase in metabolic rate over the basal rate when standing is so small, compared with a metabolic cost of moving and exercising, as to be negligible. The type of posture that involves a minimum of metabolic increase over the basal rate is one in which the knees are hyperextended, the hips are pushed forward to the limit of extension, the thoracic curve is increased, the head is projected forward, and the upper trunk is inclined backward in a posterior lean.
• Strength and flexibility.Pathological changes to the neuromuscular system (e.g., excessive wearing of the articular surfaces of joints, the development of osteophytes and traction spurs, and maladaptive changes in the length-tension development and angle of pull of muscles and tendons) may be the result of the cumulative effect of repeated small stresses (microtrauma) over a long phase of time or of constant abnormal stresses (macrotrauma) over a short phase of time (see Chapter 2). Strong, flexible muscles are able to resist the detrimental effects of faulty postures for longer phases and provide the ability to unload the structures through a change of position. However, these changes in position are not possible if the joints are stiff (hypomobile) or too mobile (hypermobile), or the muscles are weak, shortened, or lengthened.
• Age.As the human body develops from infancy to old age, several physical and neurological factors may affect posture. As discussed, at birth, a series of primary curves cause the entire vertebral column to be concave forward, or flexed, giving a kyphotic posture to the whole spine, although the overall contour in the coronal plane is straight. In contrast, the contour of the sagittal plane changes with development. At the other end of the lifespan, the aging adult tends to alter posture in several ways. A common function of aging, at least in women, is the development of a stooped posture associated with osteoporosis.
• Psychological aspects.192Not all posture problems can be explained in terms of physical causes. Atypical postures may be symptoms of personality problems or emotional disturbances.
• Evolutionary and heredity influences.192The transformation of the human race from arboreal quadrupeds to upright bipeds is likely related to the need to the male hominid to have the hands and arms available for carrying a wider variety of foods from fairly long distances. 193This transformation was responsible not only for the changes in the weight-bearing parts of the musculoskeletal structure but also for changes in the upper extremities, which are now free for the development of a greater variety of manipulative skills. In attempting to correct an individual's posture, one must be realistic and accept the limits imposed by possible hereditary factors.
• Structural deformities.The normal coronal and sagittal alignment of the spine can be altered by many conditions, including leg-length inequality (see Chapter 29), congenital anomalies, developmental problems, trauma, or disease ( Table 6-13). 194– 196
• Disease.The normal coronal alignment of the spine can be altered by many conditions, including joint degeneration and scoliosis. Scoliosis, which is a descriptive term for lateral curvature, is usually accompanied by a rotational abnormality. Scoliosis can be idiopathic, a result of congenital deformity, pain, or degeneration, or be associated with numerous neuromuscular conditions, such as leg-length inequality (see Chapter 29). Sagittal plane alignment can also be altered by disease and injury. This alteration is manifested clinically with areas of excessive kyphosis or lordosis, or a loss of the normal curves. Respiratory conditions (e.g., emphysema), general weakness, excess weight, loss of proprioception, or muscle spasm (as seen in cerebral palsy or with trauma) may also lead to poor posture. 197
• Pregnancy.Although never substantiated, postural changes have often been implicated as a major cause of back pain in pregnant women. 198, 199The relationship between posture and the back pain experienced during pregnancy is unclear. This may be because significant skeletal alignment changes that are related to back pain that are occurring at the pelvis during pregnancy but may not be directly measured by postural assessments, such as lumbar lordosis, sacral base angle, and pelvic tilt. Moore et al. 200found a significant relationship ( r= 0.49) between change in lordosis during 16–24 and 34–42 weeks of pregnancy and an increase in low back pain. Ostgaard et al. 201found that abdominal sagittal diameter ( r= 0.15), transverse diameter ( r= 0.13), and depth of the lordosis ( r= 0.11) were related to the development of back pain during pregnancy. Bullock et al., 199in the only study that used a validated and reliable posture assessment instrument, found no relationship between spinal posture (thoracic kyphosis, lumbar lordosis, and pelvic tilt) magnitude or changes during pregnancy, and back pain. The results from a study by Franklin and Conner-Kerr 202suggest that from the first to the third trimester of pregnancy, lumbar lordosis, posterior head position, lumbar angle, and pelvic tilt increase; however, the magnitudes and the changes of these posture variables are not related to back pain.
• Habit.The most common postural problem is poor postural habit and its associated adaptive changes. Poor posture, and, in particular, poor sitting posture, is considered to be a major contributing factor in the development and perpetuation of shoulder, neck, and back pain. Muscles maintained in a shortened or lengthened position eventually will adapt to their new positions. Although these muscles initially are incapable of producing a maximal contraction in the newly acquired positions, 203changes at the sarcomere level eventually allow the muscle to produce maximal tension at the new length. 204Although this may appear to be a satisfactory adaptation, the changes in length produce changes in tension development, as well as changes in the angle of pull. 205It is theorized that, if a muscle lengthens as part of a compensation, muscle spindle activity increases within that muscle, producing reciprocal inhibition of that muscle's functional antagonist and resulting in an alteration in the normal force–couple and arthrokinematic relationship, thereby effecting the efficient and ideal operation of the movement system. 204, 206– 209For example, a passively insufficient muscle is activated earlier in a movement than a normal muscle and has a tendency to be more hypertonic, thereby producing a reflex inhibition of the antagonists. 206, 207, 210, 211It is difficult to determine why a particular posture becomes dysfunctional in one individual, yet not in another. Differing adaptive potentials of the tissues between individuals may be among the causes in addition to neurologic, neurodevelopmental, and neurophysiologic factors.

Postural development begins at a very early age. As the infant starts to activate the postural system, skeletal muscles develop according to their predetermined specific uses in various recurrent functions and movement strategies. 214Jull and Janda 211215developed a system that characterized muscles based on common patterns of kinetic chain dysfunction into two functional divisions (see Table 1-4in Chapter 1):

• Postural muscles.These relatively strong muscles are designed to counter gravitational forces and provide a stable base for other muscles to work from, although they are likely to be poorly recruited, lax in appearance, and show an inability to perform inner range contractions over time.
• Phasic muscles.These muscles tend to function in a dynamically antagonistic manner to the postural muscles. Phasic muscles tend to become relatively weak compared to the postural muscles, are more prone to atrophy and adaptive shortening, and show preferential recruitment in synergistic activities. In addition, these muscles will tend to dominate movements and may alter posture by restricting movement.

The work of Jull and Janda 211also introduced the concept of postural patterns and described a lower quadrant syndrome called the pelvic crossed syndrome. In this syndrome, the erector spinae and iliopsoas are adaptively shortened (tight), and the abdominals and gluteus maximus are weak. This syndrome promotes an anterior pelvic tilt, an increased lumbar lordosis, and a slight flexion of the hip. The hamstrings frequently are adaptively shortened in this syndrome, and this may be a compensatory strategy to lessen the anterior tilt of the pelvis, 208or because the glutei are weak. In addition to increasing the lumbar lordosis, an increased thoracic kyphosis and a compensatory increase in cervical lordosis to keep the head and eyes level occurs. Janda also described an upper quadrant syndrome called the upper crossed syndrome. 215This syndrome involves adaptive shortening of the levator scapulae, upper trapezius, pectoralis major and minor, and sternocleidomastoid (SCM), and weakness of the deep neck flexors and lower scapular stabilizers. The syndrome produces elevation and protraction of the shoulder and rotation and abduction of the scapula, together with scapular winging. It also theoretically produces a forward head and hypermobility of the C4–C5 and T4 segments.

More recently, Sahrmann 204has stressed the importance of the relationship of neighboring joints along both directions of the kinetic chain to determine the mechanical cause of the symptoms.

Many studies have evaluated the effect of injury to the neuromuscular system. 216– 222If muscle control is poor, joint strain and pain may result. 223, 224Trauma to tissues that contain mechanoreceptors may result in partial deafferentation, which can lead to proprioceptive deficits and alter joint function. 225, 226For example, in addition to the mechanical restraint provided by ligaments, it has been observed that ligaments provide neurologic feedback that directly mediates reflex muscle contractions about a joint. 225, 227

As the neuromuscular system declines, certain predictable and stereotypical changes tend to occur. 228These include increased lumbar lordosis and thoracic kyphosis, decreased hip extension, decreased medial–lateral stability and increased hip flexed posture due to muscle imbalance and decreased anterior–posterior stability, decreased stride length, greater weight placed on the forefoot, increased double-foot stance time, decreased proprioception, and harder heel strike. 214As the decline progresses, the locomotor system becomes less able to adapt to its environment, requiring greater attention to recruit more sensory information in order to maintain postural control. Many of the changes that occur in the developing neuromuscular system interestingly recur in some sort of reverse order during the degrading process. 214These changes include a transition from an ankle strategy during gait back to a hip strategy, a broadened stance to combat increased medial–lateral instability, a shortened stride length to better maintain COG, decreased integration of upper body counter rotation, increased visual sensory input, and recruitment of additional afferentation for postural equilibrium, such as the use of a cane, the aid of a more posturally stable person, or both. 214

Examination

The assessment of posture primarily involves information gleaned from the history in addition to visual and palpatory observations. A clear understanding of functional anatomy and topographical landmarks is vital. 214As with gait analysis, various attempts have been made to objectively measure posture, including radiography, goniometry, inclinometry, flexible ruler measurement, photography, the Iowa anatomical position system, and plumb line assessment. Because there is an almost endless variety of activity postures and because these are extremely difficult to assess, a convenient custom has been to accept the standing posture as the individual's basic posture from which all other postures stem. 192Under this concept, ideal postural alignment for standing (viewed from the side) was defined as a straight line (line of gravity) that passes through the ear lobe, the bodies of the cervical vertebrae, the tip of the shoulder, midway through the thorax, through the bodies of the lumbar vertebrae, slightly posterior to the hip joint, slightly anterior to the axis of the knee joint, and just anterior to the lateral malleolus ( Fig. 6-5).

Theoretically, this postural alignment results in minimum stress being applied to each joint, with minimal muscle activity being required to maintain the position.

To assess posture accurately, the patient must be adequately undressed. Standard protocols for patient attire vary with respect to, among other factors, regional, societal, religious, legal, health-care specialty, gender, and age-related issues. 214Ideally, male patients should be in shorts, and female patients should be in a bra and shorts, and the patient should not wear shoes or stockings. However, if the patient uses walking aids, braces, collars, or orthoses, they should be noted and may be used after the patient has been assessed in the “natural” state to determine the effect of the appliances. 197In addition, the floor on which the patient stands and is assessed, should be a level, hard surface. A slight degree of padded carpeting is acceptable, although a hard floor is preferable. 214

The patient should assume a comfortable and relaxed posture, looking straight ahead, with feet approximately 4–6 in. apart. Often, it takes some time for the patient to adopt the usual posture because of tenseness, uneasiness, or uncertainty. 197For the static examination, the clinician must be oriented to the patient so that the dominant eye ( Table 6-14) is located in the midline between the landmarks being compared. The static assessment of posture is initially performed in a global fashion, with the patient in the standing, sitting, and lying (supine and prone) positions. 197Although it may seem contrary, unassisted still, upright postural stance requires greater stability than unassisted walking, which is why walking occurs first in the toddler. 214During mature still, upright stance, the hip joints account for the majority of medial–lateral stability, while the ankle joints account for a great deal of anterior–posterior stability. 229

When observing a patient for abnormalities in posture, the clinician looks for asymmetry. 197Regional asymmetry should trigger further evaluation of that area, but asymmetry alone does not confirm or rule out the presence of dysfunction. As some asymmetry between left and right sides is normal, the clinician must make the determination as to whether the apparent deviation is normal or caused by pathology. It must be remembered that postural adaptations can occur in a number of ways, including changes in gait, joint loading, neural function, muscle coordination, respiratory function, endurance, strength, and balance. 214After the patient has been examined in the aforementioned positions, the examiner may decide to include other habitual, sustained, or repetitive postures assumed by the patient to see whether these postures increase or alter symptoms. 197

Static Examination

The static postural examination, as it relates to each joint and the various postural syndromes that exist, is described in the relevant chapters. A summary of the most common findings and faults are listed in Table 6-13. Common lower limb skeletal malalignments and possible correlated and compensatory motions or postures are compiled in Table 6-15.

Due to the relationships between head, neck, thorax, lumbar spine, and pelvis, any deviation in one region can affect the other areas. A number of common postures are described here.

• Pelvic and lumbar region.The more common faulty postures of the pelvic and lumbar region include 230
  • Lordotic posture.( Fig. 6-6) It is characterized by an increase in the lumbosacral angle, an increase in lumbar lordosis, and an increase in the anterior pelvic tilt and hip flexion. 231This posture is commonly seen in pregnancy, obesity, and those individuals with weakened abdominal muscles. Potential muscle impairments include
    • decreased mobility in the hip flexor muscles (iliopsoas, tensor fascia latae, rectus femoris) and lumbar extensor muscles (erector spinae);
    • impaired muscle performance due to stretched and weakened abdominal muscles (rectus abdominis, internal and external obliques, and transversus abdominis).

This posture places stress throughout the lumbar spine on the anterior longitudinal ligament, the zygapophyseal (facet) joints, and narrows the posterior disk space and the intervertebral foramen, all of which are potential sources of symptoms.

• Slouched posture: This posture, also referred to as the swayback, 182is characterized by a shifting of the entire pelvic segment anteriorly, resulting in relative hip extension, and a shifting of the thoracic segment posteriorly, resulting in a relative flexion of the thorax on the upper lumbar spine ( Fig. 6-6). As a result, there is an increased lordosis in the lower lumbar region, increased kyphosis in the thoracic region, and usually a forward (protracted) head. This posture is commonly seen throughout most age groups and is typically the result of fatigue or muscle weakness. Potential muscle impairments include the following:
  • Decreased mobility in the upper abdominal muscles (upper segments of the rectus abdominis and obliques), internal intercostal, hip extensor, and lower lumbar extensor muscles and related fascia.
  • Impaired muscle performance due to stretched and weakened lower abdominal muscles (lower segments of the rectus abdominis and obliques), extensor muscles of the lower thoracic region, and hip flexor muscles.

This posture places stress on the iliofemoral ligaments, the anterior longitudinal ligament of the lower lumbar spine, and the posterior longitudinal ligament of the upper lumbar and thoracic spine. In addition, there is narrowing of the intervertebral foramen in the lower lumbar spine and approximation of the zygapophyseal (facet) joints in the lower lumbar spine.

• Flat low back posture.This posture is characterized by a decreased lumbosacral angle, decreased lumbar lordosis/extension, and posterior tilting of the pelvis ( Fig. 6-6). This posture is commonly seen in those individuals who spend long periods slouching or flexing in the sitting or standing positions. The potential muscle impairments include
  • decreased mobility in the trunk flexor (rectus abdominis, intercostals) and hip extensor muscles;
  • impaired muscle performance due to stretched and weak lumbar extensor and possibly hip flexor muscles.

This posture can apply stress on the posterior longitudinal ligament, the posterior disk space, and on the normal physiological lumbar curve, which reduces the shock-absorbing effects of the lumbar region and predisposes the patient to injury.

• Cervical and thoracic region.The more common faulty postures of the cervical and thoracic region include 230
  • Round back with forward head.This posture is characterized by increased kyphotic thoracic curve, protracted scapulae (round shoulders), and forward head (excessive flexion of the lower cervical spine and hyperextension of the upper cervical spine) ( Fig. 6-7). The causes for this posture are similar to those found with the flat low back posture. The potential muscle impairments include the following:
  • Decreased mobility in the muscles of the anterior thorax (intercostal muscles), muscles of the upper extremity originating on the thorax (pectoralis major and minor, latissimus dorsi, serratus anterior), muscles of the cervical spine and head that attach to the scapular and upper thorax (levator scapulae, SCM, scalene, upper trapezius), and muscles of the suboccipital region (rectus capitis posterior major and minor, obliquus capitis inferior and superior).
  • Impaired muscle performance due to stretched and weak lower cervical and upper thoracic erector spinae and scapular retractor muscles (rhomboids, middle trapezius), anterior throat muscles (suprahyoid and infrahyoid), and capital flexors (rectus capitis anterior and lateralis, superior oblique longus colli, longus capitis).

This posture can place excessive stress on any or all of the following structures:

• Anterior longitudinal ligament in the upper cervical spine and posterior longitudinal ligament in the lower cervical and thoracic spine.
• Irritation of the zygapophyseal (facet) joints in the upper cervical spine.
• Impingement on the neurovascular bundle from anterior scalene or pectoralis minor muscle tightness (thoracic outlet syndrome).
• Impingement of the cervical plexus from levator scapulae muscle tightness.
• Temporomandibular joint dysfunction.
• Lower cervical disk lesions.
• Flat upper back and neck posture. This posture is characterized by a decrease in the thoracic curve, depressed scapulae, depressed clavicles, and decreased cervical lordosis with increased flexion of the occiput on the atlas. Although not common, this posture occurs primarily with exaggeration of the military posture ( Fig. 6-8). The potential muscle impairments include the following:
  • Decreased mobility in the anterior neck muscles, thoracic erector spinae, and scapular retractors, with potentially restricted scapular movement, which can interfere with shoulder elevation.
  • Impaired muscle performance in the scapular protractor and intercostal muscles of the anterior thorax.

This posture can place stress on the neurovascular bundle in the thoracic outlet between the clavicle and ribs and can decrease the shock-absorbing function of the kyphotic curvature, thereby predisposing the neck to injury.

Forward Head

Forward head posture is described (in sitting or standing) as the excessive anterior positioning of the head, in relation to a vertical reference line, increased lower cervical spine lordosis, and rounded shoulders with thoracic kyphosis. Other postural adaptations associated with the forward head posture include protracted scapulae with tight anterior muscles and stretched posterior muscles and the development of a cervicothoracic kyphosis between C4 and T4. 207, 232, 233For each inch that the head is anterior to the COG, the weight of the head is added to the load borne by the cervical structures. 234For example, the average head weighs 10 lb. If the chin is 2 in. anterior to the manubrium, 20 lb is added to the load. If normal motion is undertaken in this poor postural environment, the result may be abnormal strain placed on the joint capsule, ligaments, intervertebral disks (IVDs), levator scapulae, upper trapezius, SCM, scalene, and suboccipital muscles.

Sustained forward head postures may cause a painful fatigue in the levator scapulae, rhomboids, and lower portion of the trapezius, a condition referred to as tired neck syndrome. 235The traumatized muscles may cause pain, which in turn causes the patient to restrict motion. Patients with these postural abnormalities may experience myofascial pain that can cause referral zone pain. 195This myofascial pain is thought to be caused by waste products produced by the muscles or from localized ischemia of those structures. An underlying cycle of abnormal relaxation in some muscles, with shortening, stretching, and a loss of tone in others, occurs during this process, with resultant joint strain and dysfunction.

As the head is brought forward by flexing the cervical segments, the scalene muscles are permitted to adaptively shorten, thus lessening the support of the upper ribs. The cervical flexion is followed by an increase of the thoracic curvature, and the tension of the spinal musculature increases. 236, 237In this position, capital extension must now occur to keep the eyes horizontal and allow the individual to look ahead. 182, 238, 239This occipital hyperextension of the cranium on the cervical spine has been related to head, neck, and temporomandibular joint pain. A postural-pain relationship has been described by Willford and colleagues 240in people wearing multifocal corrective lenses.

Under normal circumstances, the COG for the head falls slightly anterior to the ear. The habitual placement of the head anterior to the COG of the body places undue stress on the temporomandibular joint, the cervical and upper thoracic facet joints (especially at the cervicothoracic junction), and the supporting muscles. 183, 184

The abduction of the scapulae or protraction of the shoulders causes a lowering of the coracoid process, producing adaptive shortening of the pectoralis minor, which, in turn, may flatten the anterior chest wall and alter the motion of the scapula, producing a mechanical impairment of the shoulder.

Protraction of the shoulder girdles also limits extension of the upper thoracic spine, which, in turn, limits elevation and abduction of the shoulders. This alteration can lead to a hypermobility or instability of the glenohumeral joint and overuse syndromes of the shoulder elevators or abductors. Shoulder protraction also causes the humerus to rotate internally which stretches the posterior glenohumeral joint capsule; in addition, it increases the anterior force at the joint as a result of gravity. The former may lead to posterior instability and rotatory hypermobility, and the latter to anterior instability and a biceps tendonitis, as this muscle becomes overused in its attempt to stabilize the glenohumeral joint.

The anteriorly displaced line of gravity induced by the forward head posture has an effect on respiration. This change in posture is postulated to have the following consequences 241:

1. Open-mouth breathing.242Open-mouth breathing is the normal pattern of breathing for a newborn. This pattern of breathing becomes abnormal if it persists into the 5–7 years. A child with a long bout of sinus infections and blockages is forced to use mouth breathing as the primary method of breathing. With the development of the teeth and tongue, the oral passageway for air is gradually reduced, forcing the child to open the mouth further in order to breathe. It is postulated that this can result in 243–245:

   • a failure to filter inspired air of pathogens and particles. These particles go directly into the alveoli, producing an inflammatory reaction in the lungs that results in bronchospasm or asthma and stimulates a future hypersensitivity to any new particles;
   • a failure to humidify inspired air, so that the air entering the lungs is dry;
   • a failure to warm the inspired air. Cold or cool air entering the lungs stimulates an increased presence of white blood cells, increasing the hypersensitivity of the lungs. Early intervention with mouth breathers is essential, and it is recommended that the child be encouraged to keep the tongue against the roof of the mouth while breathing.

2. Thoracic hyperflexion.Although only theoretical, the thoracic compensation is necessary to counteract the backward tilting of the head and to return the eyes to a horizontal position. This compensation produces the following:

   • A reduction in thoracic extension.
   • A reduced ability of the ribs to elevate during inspiration, resulting from a reduced ability of the thoracic cavity to expand during inspiration. 243– 245
   • An increase in the respiratory rate. 243– 245
   • A shortening of the scalene muscles. Because of their newly acquired shortened position, the muscles have a reduced ability to contract, resulting in a reduced ability to elevate the first rib; a reduced ability to increase the vertical dimension of the thoracic cavity during inspiration 242−244; and an increase in apical breathing. 243– 245

The forces from the cervical and thoracic regions of the spine can be transmitted to the lumbar spine, increasing the lordotic curve. 246, 247The exaggeration of the lumbar curve is accompanied by a shift of the weight to the posterior part of the vertebral bodies and to the articular processes, producing maximum joint strain of the lumbosacral junction and a forward inclination of the pelvis.

The increased forward inclination of the pelvis may produce a shortening of the erector spinae group and flexors of the hip, accompanied by a lengthening of the abdominal and hamstring muscles. These muscle imbalances serve to maintain the deformity. 248

The intervention for forward head is outlined in Chapter 25.

Dynamic Examination

It should be apparent that any postural examination should include a dynamic assessment, as a static examination alone cannot demonstrate the effect of a particular posture on function. A dynamic examination that assesses functional movement patterns, such as the Selective Functional Movement Assessment249, 250, helps the clinician to ascertain whether the apparent postural abnormality is dysfunctional. The Selective Functional Movement Assessment assesses functional movement using four categories:

• Functional and nonpainful
• Functional and painful
• Dysfunctional and nonpainful
• Dysfunctional and painful

Within these categories, the term functionaldescribes any unlimited or unrestricted movement, whereas the term dysfunctionalis used to describe movements that are limited or restricted and which reproduce pain and/or demonstrate a lack of mobility, stability, or symmetry within a given functional movement. Although most clinicians can appreciate that repeated movement patterns performed in a therapeutic manner may be beneficial, it must also be remembered that repeated motions performed erroneously can produce changes in muscle tension, muscle strength, length, and stiffness. 204It is quite normal for muscles to frequently change their lengths during movements. However, this change in resting length may become pathologic, when it is sustained through incorrect habituation or as a response to pain.

The dynamic postural examination can also be designed to assess each joint to its extremes of motion. The following should serve as a guideline:

• Joints of the extremities: active movements through the full range of each direction for each joint, with passive overpressure and a maximum isometric contraction applied at the end range. Combined motions should also be assessed, for example, elbow flexion and supination.
• Joints of the spine: flexion, extension, side bending, and rotation of the cervical, thoracic, and lumbar spine in sitting, standing, and lying as appropriate. Combined motion should also be assessed, for example, cervical flexion with rotation superimposed on the flexion.
• Functional movements: deep squatting (heels flat and shoulders flexed), Apley scratch test (fingertips touching behind the back).

During these various movements, the clinician is looking for symmetry, ease of movement, and the provocation of any symptoms.

Special Tests

The special tests used in the assessment of posture include all those that are related to the assessment of muscle length and strength. Examples include manual muscle testing, the Thomas test, and the Ober test. These tests are described in the relevant chapters. In addition, the clinician should examine neurodynamic mobility for the presence of adverse neural tension (see Chapter 11).

Intervention

The focus of therapeutic intervention for posture and movement impairment syndromes is to alleviate symptoms and to play a significant role in educating the patient against habitual abuse. Interestingly, despite the widespread inclusion of postural correction in therapeutic interventions, there is limited experimental data to support its effectiveness. Therapeutic exercise programs for the correction of muscle imbalances traditionally focus on regaining the normal length of a muscle, so that good movement patterns can be achieved. The intervention of any muscle imbalance is divided into three stages:

1. Restoration of normal length of the muscles. If the muscle activity is inhibited, the muscle should be stretched in the inhibitory phase. If the muscle is hypertonic, muscle energy techniques may be used to produce minimal facilitation and a minimal stretch. With true adaptive shortening of the muscle, stronger resistance is used to activate the maximum number of motor units, followed by vigorous stretching of the muscle.

2. Strengthening of the muscles that have become inhibited and weak. Vigorous strengthening should be initially avoided to prevent substitutions and the reinforcement of poor patterns of movement.

3. Establishing optimal motor patterns to secure the best possible protection to the joints and the surrounding soft tissues.

In addition to using specific techniques to stretch and strengthen muscles, muscle energy (see Chapter 10), proprioceptive neuromuscular facilitation, and the incorporation of a more “wholistic” approach can often have a beneficial effect on postural dysfunction and movement impairment. There is a growing interest in the field of integrative care—the blending of complementary or wholistictherapies with conventional medical practice. Wholistic approaches provide whole-person care—addressing people rather than diseases, caring rather than curing, using all possible therapeutic modalities rather than a limited few, and empowering patients wherever possible to use self-care approaches and to be active participants in decisions regarding their health.

Examples of these “wholistic” approaches, currently used in association with physical therapy, include the Alexander technique, Feldenkrais method, Trager psychophysical integration (TPI), Pilates, Tai Chi Chuan (TCC), and yoga.

Alexander Technique

The Alexander technique 251is commonly viewed as a series of breathing and posture techniques. However, the purpose of the technique is to make patients more aware of structural imbalances, different ways of moving, and the excessive tensions that can be produced in activities of daily living. Although it is not within the scope of this chapter to fully describe the Alexander technique, some of its principles are outlined here, and the reader is encouraged to learn more about this technique through further reading.

The Alexander technique uses reeducation to change the thought processes, as well as the postural and movement habits, that are theorized to provoke pain. According to this theory, the main reflex in the body, termed the primary control, which is situated in the area of the neck, controls all of the other reflexes of the body. Dysfunction of this main reflex, resulting from increased tension in the neck, causes a pulling back of the head and changes the relationship of the neck and back, eventually causing tensions in other parts of the body.

Based on these assumptions, Alexander devised three directions251:

1. Allow the neck to be free.The purpose of this direction is to eliminate any excess tension in the muscles of the neck.

2. Allow the head to go forward and upward.When the neck muscles are released, the head goes slightly forward and upward.

3. Allow the back to lengthen and widen.As the head moves slightly forward and upward, the spine lengthens. Because an increase in the spine length can also narrow the spine, widening of the back, through a retraction of the shoulders and broadening of the rib cage, is encouraged.

Feldenkrais Method

The Feldenkrais method of somatic education is a self-discovery process using movement. It was developed by Dr Moshe Feldenkrais, a physicist and electronics engineer. The aim of the Feldenkrais method is for an individual to move through relaxation and self-awareness, with minimum effort and maximum efficiency. The method teaches that many pains and movement restrictions are the result not of an actual physical defect or the inevitable deteriorations of age, but of habitual poor use. 252Over time, this causes fatigue, disability, and pain.

The antidote, according to Feldenkrais, is to relearn certain functional movements and postures using the so-called organic learning style, based on the way humans learn to perform, as they develop during early childhood. During this growth phase, some of the movements are learned correctly, others are not. Incorrect movement patterns may result in inefficient movements or restrictions to movements. In humans, the premotor cortex relates to posture stability and the act of reaching. It is also the supplementary motor area for planning, programming, and initiating movement. 253These latter components require correct sequencing and organization. The Feldenkrais method is seen as a way of reprogramming the nervous system and reteaching the body how to perform the functional movement patterns correctly.

Functional movement patterns involve the integration and sequencing of movement patterns while maintaining neuromuscular control. These patterns and postures are developed using the two aspects of the Feldenkrais method: awareness through movement (ATM) and functional integration (FI). Although closely related, ATM and FI have fundamental differences:

• ATM is usually done in a group, whereas FI involves one-on-one learning.
• ATM involves the performance of gentle exploratory movements using verbal guidance. In contrast, FI uses guidance into nonhabitual movements, with tactile cueing by a trained practitioner.

Both the aspects work toward changing old movement patterns or creating new movement patterns. Individuals are led through a series of movement sequences. All movements are performed slowly, without pause and short of the range of discomfort and pain. The proponents of the Feldenkrais method claim that these movements promote improved attention and awareness. 254It is also claimed that these movements refine the ability to detect information and make perceptual discriminations. 254Regular use of such attentive explorations and integration of the skills lead to an automatic use of these motor abilities. An example of a Feldenkrais exercise is to move one's head in one direction and one's shoulder and eyes in the other. 255These movement sequences are usually repeated a number of times.

Five key principles are involved in the development of the Feldenkrais method: 254, 256

1. Self-organization: Dynamic systems theorists believe that behaviors are assembled in the moment and context of the current movement task.

2. Behavior is dynamic and plastic.

3. Perturbation is the instrument of change.

4. Choice is necessary.

5. Human development follows a logical sequence.

The Feldenkrais method is both educational and experimental. It is process-, not goal-, oriented and is entirely pragmatic. 257With acute conditions, the patient is started in the position of maximum comfort. The lesson then uses any movement, however small, within the limit of comfort. The patient is encouraged to become aware of the smoothness and clarity of the movement. The movement is repeated and practiced. Further movements within this framework are investigated and practiced. These movements are simple initially, becoming more complex as the patient gains confidence. 257

Trager Psychophysical Integration

TPI is a multifaceted intervention, consisting of light, gentle, and painless movements to facilitate the release of deep-seated physical (and mental) patterns. 258TPI was designed at the beginning of the twentieth century by Dr Milton Trager and has been shown to be effective in promoting mobility and decreasing pain for patients with a wide variety of diagnoses, including cerebral palsy, 259chronic spinal pain and dysfunction, 260and arthritis. 258, 261

According to TPI philosophy, detrimental physical patterns are those developed by poor posture, trauma, stress, and poor movement habits. 262Trager techniques serve to produce overall relaxation on the part of the patient, developing a sense of integration and effortless movement through a series of guided movements and mental gymnastics. 263, 264

The Trager approach is broken down into two components: tableworkand mentastics.

Tablework

Tablework consists of a series of gentle and painless movements that resemble general mobilization techniques. The body of the patient is passively moved by the clinician who looks and feels for involvement of the tissue. The aim is to provoke a feeling of softness and freedom to motion throughout the body. 260Using these movements, the entire body is mobilized. Rhythmic rocking motions are initiated during these movements to stimulate the vestibular and reticular activating systems of the patient. This is theorized to produce an overall sense of relaxation and well-being through an inhibition of the sympathetic system and the facilitation of the parasympathetic system. 265

Mentastics

Mentastics is a system of active movements, designed to enhance the feeling of well-being provided by the tablework exercises. Mentastics encourage the patient notto control the movement, as in traditional exercise, but to let goof the control. 260The patient is taught to listen to signals of pain and fatigue and to change the symptoms by altering the movement. Over time, the patient learns how to move comfortably and to release tension. 264

Pilates

The Pilates method of body conditioning (Pilates Inc.) is a technique and apparatus developed in the 1940s by Joseph Pilates, who was prone to chronic illness as a child.

The Pilates method was first embraced by the dance community, but its inherent concept of core stabilization, mind–body awareness, and control of movement and posture has since been used successfully in rehabilitation, for the development of overall strength and fitness in patients with back pain, balance deficits, and urinary incontinence due to pelvic floor muscle weakness.

The Pilates method uses many of the concepts and techniques that physical therapists commonly employ, with an increased emphasis on neuromuscular control. As such, the Pilates method focuses on motor training, rather than on motor strength, using precise and controlled exercises. The Pilates method stresses the importance of the so-called powerhouse muscles of the body; deep, coordinated breathing; postural symmetry; and controlled movement. According to the Pilates method, the powerhouse muscles include the transversus abdominis, the lumbar multifidus, the pelvic floor muscles, and the diaphragm muscle. Approximately 10 repetitions are needed for each exercise.

The Pilates exercises emphasize the maintenance of a neutral spine throughout machine and mat exercises. Many of the Pilates exercises involve squeezing the inner thighs together in the Pilates stance, while simultaneously engaging the pelvic floor muscles, in an effort to increase trunk stability. The Pilates stanceinvolves slight external rotation in both hips and lower extremities, while maintaining the thighs in firm contact. Other Pilates exercises include instructions on how to isolate a transversus abdominis contraction from the rest of the abdominal muscles. This is commonly achieved using the verbal cueing of “pull your belly button toward your spine.” This contraction is then practiced in a variety of positions and techniques, in order to enhance spinal, or core, stability. Pelvic stability is encouraged with such verbal cueing as “pull your sitting bones together,” thereby producing a contraction of the ischiococcygeal muscle that provides support for the pelvic contents, in addition to contributing to sacroiliac joint stability.

Although many of the Pilates exercises can be performed on mats, specially designed Pilates equipment may also be used. Four basic machines comprise the Pilates equipment line:

1. Reformer.This is the basic machine of the Pilates method. It resembles a twin bed in size and frame and is equipped with handholds, pulleys, and cables that exercisers push or pull with their hands or feet. The reformer usually is used in the rehabilitation of hamstring tears, stress fractures, and low back injuries.

2. Cadillac or trapeze table.This piece of equipment is equipped with multiple bars and straps and features a pull-down bar. It is used for overall conditioning.

3. Multichair.The multichair is the equipment of choice for footwork and for ankle rehabilitation. It can be adapted for such activities as one-arm pushes, lunges, and dips.

4. Ladder-barrel.This piece of equipment consists of a sliding base and five rungs and is used for a variety of strengthening and flexibility exercises.

The use of Pilates apparatus to train stabilization strategies during movement may enhance the effect of the more relatively static mat exercises.

Tai Chi Chuan

TCC is a Chinese low-speed and low-impact conditioning exercise and is well known for its slow and graceful movements. During the practice, diaphragmatic breathing is coordinated with graceful motions to achieve mind tranquility.

Classical Yang TCC includes 108 postures, with some repeated sequences. Each training session includes 20 minutes of warm-up, 24 minutes of TCC practice, and 10 minutes of cool down. 240Warm-up exercise is very important, because it may enhance TCC performance and prevent injury. It usually includes 10 movements (ROM exercises, stretching, and balance training), with 10–20 repetitions. 266

The exercise intensity of TCC depends on training style, posture, and duration. 267, 268A high-squat posture and short training duration are suited to those with low levels of fitness or elderly participants; a low-squat posture and longer durations are suited to healthy or younger participants. 266

Recent investigations have found that TCC is beneficial to cardiorespiratory function, 269strength, 270balance, 270, 271flexibility, 271microcirculation, 272and psychological profile. 267Hartman and colleagues 273also reported that TCC could control fatigue and regulate pain during activities and could improve walking speed and self-care activities in patients with osteoarthritis.

Yoga

Yoga, a literal translation from the Sanskrit word for “union,” is a 5000-year-old Indian practice. There are 40 main schools of yoga philosophy, of which Hatha (pronounced haht-ha) yoga is the most popular in the United States. According to Indian tradition, Hatha yoga is one of the four main traditions of Tantra yoga, a holistic approach to the study of the universe from the point of the individual. Hatha yoga is based on the practice of physical postures (asanas), breath control (pranayama), and meditation in order to energize subtle channels of the mind called nadis.

• Asanas.Physical postures that are performed using isometric contractions and held firmly from a time that ranges from seconds to minutes. There are 84 basic asanas in Hatha yoga, which are categorized in accordance with the movement they create in the body.
• Pranayama.Yoga breathing is performed slowly and without strain throughout the routine, with a brief pause of 1–2 seconds after each inhalation and exhalation.

The theoretical benefits associated with yoga encompass physiological, psychological, psychomotor, cognitive, and biochemical aspects. The physiological, psychological, psychomotor, and cognitive benefits include reduced stress; improved attention, memory, and learning efficiency; decreased pulse rate, respiratory rate, and blood pressure; and increased muscular strength and aerobic and muscular endurance. 274– 281The biochemical benefits include an increase in high-density lipoprotein cholesterol, a decrease in low-density lipoprotein cholesterol, and an increase in hematocrit levels. 274

• 1. List the two phases and three tasks of the gait cycle.

• 2. List, in order of occurrence, the eight intervals of the gait cycle.

• 3. As speed increases, what effect is there on the stance phase and the double stance phase?

• 4. True or false: The thoracic spine and the pelvis rotate in opposite directions to each other during the gait cycle.

• 5. From midstance to terminal stance, in which direction should the ilium rotate?

• 6. Describe the characteristics of the lower crossed syndrome.

• 7. List five causes of postural dysfunction.

• 8. Describe the different characteristics of the two functional divisions of muscles outlined by Janda and Jull.

Answers