Chapter 8. The Intervention

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

1. Understand and describe the principles of a comprehensive rehabilitation program during the various phases of healing.

2. Discuss the various components of the intervention and their respective importance.

3. List the clinical tools that can be used to decrease pain and inflammation and promote healing.

4. Discuss the intrinsic and extrinsic stimuli that can be used to promote and progress healing.

5. Describe the benefits of each of the electrotherapeutic modalities.

6. Describe the benefits of each of the physical agents and mechanical modalities.

7. Understand the rationale for the therapeutic techniques used in each of the three stages of healing.

8. Understand the importance of patient education.

The purpose of the physical therapy intervention is to safely return a patient to his or her preinjury state, with as little risk of reinjury as possible and with the minimum amount of patient inconvenience. Normally, this is achieved with a gradual progression of strengthening and flexibility exercises, while avoiding further damage to an already compromised structure.1 For the contractile tissues, such as the muscles, this is accomplished through measured rest, rehabilitative exercise, high-voltage electrical stimulation, central (cardiovascular) aerobics, general conditioning, and absence from abuse.2 The inert structures, such as ligaments and menisci, rely more on the level of tension and force placed on them for their recovery, which stimulates the fibroblasts to produce fiber and glycosaminoglycans.3 The progression to high-functional demands or sports-specific exercises may be made, depending on the patient's requirements. For the athlete, the criteria for return to play should include no pain, full pain-free ROM, normal flexibility/strength/balance, good general fitness, normal sports mechanics, and demonstration of sports-specific skills.4

According to the “Guide to Physical Therapist Practice,”5 an intervention is “the purposeful and skilled interaction of the physical therapist and the patient/client and, when appropriate, with other individuals involved in the patient/client care, using various physical therapy procedures and techniques to produce changes in the condition consistent with the diagnosis and prognosis.”

Three components comprise the physical therapy intervention: coordination, communication, and documentation; patient/client-related instruction; and direct interventions (Box 8-1).5

An intervention is most effectively addressed from a problem-oriented approach and is based on the patient's functional needs and on mutually agreed-upon goals.5 Decisions about the intervention are made to improve the patient's ability to perform basic tasks and to restore functional homeostasis. The most successful intervention programs are those that are custom designed from a blend of clinical experience and scientific data, with the level of improvement achieved being related to goal setting and the attainment of those goals (Table 8-1). The necessary knowledge to perform an intervention includes6

• the temporal phases of tissue healing, common problems associated with each phase, and stresses that tissues can safely tolerate during each phase;
• movement characteristics including amount of range, control, and capacity required for various functional activities;
• the range of available intervention strategies and procedures to promote healing and corresponding outcomes in varied patient populations;
• sequencing of various interventions to challenge appropriately involved tissues and the whole patient. For example, being able to recognize the underlying tissue healing and balance disorders in a patient status posthip fracture with diabetes mellitus, the need for aerobic conditioning in assessing patients with low back dysfunction, and the importance of body mechanics education in prenatal and postnatal exercise classes; and
• intervention strategies to promote overall health and well-being, and to prevent secondary dysfunction.

Whether the identification of the specific structure or structures causing the dysfunction is necessary, in order to proceed with an intervention, remains controversial. Cyriax8 designed his examination process to selectively stress specific tissues in order to identify the structure involved and its stage of pathology. In contrast, McKenzie9 and Maitland10,11 seldom identified the involved structure, believing that it is not always possible, or even necessary, for the prescription of appropriate therapeutic interventions. Indeed, based on the Maitland and McKenzie philosophy, the therapeutic strategy is determined solely from the responses obtained from tissue loading and the effect that loading has on symptoms.9 Once these responses have been determined, the focus of the intervention is to provide sound and effective self-management strategies for patients, which avoid harmful tissue loading.9 However, although self-management must be encouraged whenever feasible, these strategies have their limitations. One cannot realistically expect the majority of patients to fully rehabilitate themselves with a condition that requires the integration of a multitude of decision-making processes such as occurs with a total joint replacement, or an anterior cruciate ligament reconstruction.

Many interventions for musculoskeletal disorders have shown small effects when tested in randomized controlled trials. Identifying patients who respond best to certain treatments has received increased interest in research activity. With a clinical prediction rule (CPR), a combination or cluster of patient characteristics is used to determine the diagnosis, prognosis, or likely response to treatment of that individual.12 The development of a CPR involves the following stages: derivation (analyzing a data set to establish a rule with predictive power), narrow validation (evaluating the rule in a similar clinical setting and population), broad validation (evaluating the rule in multiple clinical settings), and impact analysis (determining whether the rule changes clinicians' behavior, improves patient outcomes, or reduces costs).12 Thus far, however, all of the CPRs have been derived using single-arm study designs and, therefore, the results of these studies must be interpreted with caution, as these CPRs run a greater risk of identifying prognostic factors rather than factors that modify the effect of a treatment.13 Other important limitations of many of the current CPRs are the use of short-term outcomes only, arguably trivial findings, and limited rule application potential.13 To date, only one CPR on spinal manipulation for low back pain14 underwent validation in a controlled trial and can be considered for clinical application (and only in a population similar to that tested).13

The intervention is typically guided by short- and long-term goals, which are dynamic in nature, being altered as the patient's condition changes, and strategies with which to achieve those goals based on the stages of healing (Table 8-1). Intervention strategies can be subdivided into active (direct) or passive (indirect), with the goal being to make the intervention as active as possible at the earliest opportunity.

Many factors can contribute to the patient's resistance to improvement. In some cases, it may be an individual factor that, when eliminated, will allow the patient to respond well. In the majority of cases, the resistance to improvement is based on the interaction of multiple factors, which must be recognized and corrected.

Misjudgments are sometimes made with the intervention. In general, the patient's pain should not last more than a couple of hours after an intervention. Pain that lasts longer than 2 hours is usually an indication that the intensity of the intervention, rather than the intervention itself, has been inappropriate. The clinician has to remove the notion that all pain is bad. In many respects, a slight increase in pain following an intervention is a more desirable finding than no change in pain, because it indicates that the correct structure is being stressed, albeit too aggressively.

Acute Phase

Clinical findings during the acute stage are associated with inflammation and include pain, edema, redness, heat, and impairment or loss of function (see Chapter 2). Although the redness and heat are not necessarily problems that require a specific treatment goal, pain, edema, and loss of function certainly are. Given the number of pathologic entities that can be evoked by the repair process, such as complex regional pain syndrome (CRPS, previously referred to as reflex dystrophy) and myositis ossificans, it is clear that neurophysiologic processes are at work. Usually, during the acute phase, there is pain at rest or with active motion, or when specific stress is applied to the injured structure. The pain, if severe enough, can result in muscle guarding and loss of function. With passive mobility testing, pain is reported before tissue resistance is felt by the clinician.

Pain

A major focus of physical therapy is the control of pain. At the simplest level, the transmission of information relating to pain from the periphery to the cortex is critically dependent on integration at three levels within the central nervous system: the spinal cord, brain stem, and forebrain (see Chapter 3). Although pain serves as a protective mechanism, allowing an individual to be aware of a situation's potential for producing tissue damage and to minimize further damage, it can persist beyond its usefulness. In addition, the presence of pain can stimulate muscle spasm, which in turn can lead to circulatory deficiency, muscle atrophy, and loss of function. The challenge for the clinician during the various phases of healing is to control the pain while simultaneously progressing the patient. To control the pain, the source of pain must be first identified. Once identified, several different approaches can be used to provide pain relief as follows15:

• Encourage the body's central biasing mechanisms (see Chapter 3) through the use of cognitive processes (motivation, relaxation techniques, positive thinking, and mental focus).
• Minimize further tissue damage through the application of the principles of PRICEMEM (protection, rest, ice, compression, elevation, manual therapy, early motion, and medications—see later). Therapeutic modalities are probably the most frequently used tool in all of musculoskeletal rehabilitation. Physical agents, including therapeutic cold, heat, sound, light, diathermy, electrical current, massage, and compression can be used throughout the rehabilitation program at appropriate times. Clearly, an understanding of the physiological basis for using these agents is critical if clinicians are to use these agents effectively. During the acute phase, physical agent interventions (therapeutic cold and compression) should be applied as soon as possible after the injury to help control pain.
• Educate the patient as to the rationale of the treatment and what he or she can expect.
• Recognize that all pain, even psychosomatic pain, feels very real to the patient.

Inflammation and Edema

Inflammation and edema occur as part of the healing process (see Chapter 2). In addition to controlling pain, the goals during the initial phase of intervention for an acute lesion are to control the inflammation and edema and to protect the damaged structures from further damage, while attempting to promote and progress tissue healing and increase function.

Loss of Function

Neuromuscular inhibition can result from pain and joint effusion and should be addressed as early as possible. Function can be enhanced through the use of assistive and supportive devices (crutches, canes, sling, immobilizer, etc.).

PRICEMEM

• Protection Excessive tissue loading must be avoided. For example, in the lower extremity when ambulation is painful, crutches or other assistive devices are advocated until the patient can bear weight painlessly.16
• Rest. Rest is generally defined as absence from abuse, rather than a complete absence from activity.2 Prolonged immobilization can have a detrimental effect on muscles, ligaments, bones, collagen, and joint surfaces. In response to the training stimulus, the involved components will undergo some breakdown at the subcellular, cellular, or tissue level, which will temporarily lower the functional ability of each. A rest period allows the body to adapt by resynthesizing the protein in these structures to a higher level than before the overload.17–19 This process of synthesizing takes between 12 and 48 hours depending on the intensity (quality) of the exercise and the volume (total amount) of the load.20 However, it is important to remember that if the training stimulus is stopped, reduced, or altered too much, the training effect will decline.
• Ice. The therapeutic application of cold or cryotherapy has been used as a healing modality since the days of the ancient Greeks.21 Garrick16 recommends that ice be used until the swelling has ceased. Limiting the effusion serves to hasten the healing process by minimizing the amount of extracellular fluid and hematoma to be reabsorbed.22,23
• Compression. The most common method of applying compression is via an elastic bandage.24 Compression provided by a pneumatic device,25,26 or by a felt pad incorporated into an elastic wrap or taping,27 has also been demonstrated to be effective in decreasing effusion.
• Elevation. Elevation of an extremity aids in venous return and helps minimize swelling. Elevation and compression should be continued until the swelling has completely dissipated.16
• Manual Therapy. The controlled application of various manual techniques can have several therapeutic benefits (see Chap. 10). These benefits are theoretically achieved through28,29
  • stimulation of the large-fiber joint afferents of the joint capsule, soft tissue, and joint cartilage, which aids in pain reduction;
  • stimulation of endorphins, which aids in pain reduction;
  • decrease of intra-articular pressure, which aids in pain reduction;
  • mechanical effect, which increases joint mobility;
  • remodeling of local connective tissue;
  • increase of the gliding of tendons within their sheaths; and
  • increase in joint lubrication.

Manual techniques, which are discussed in Chapter 10, allow the clinician to choose the degree of specificity of an intervention. Although the goal is to be as specific as possible, there are many times when a general technique is appropriate. General techniques are typically less aggressive, are applied to the larger muscle groups or regions, and often can be performed by the patient as part of the home exercise program. General manual therapy techniques that can be used during this stage include gentle massage to increase blood flow. Specific manual techniques that can be used during this stage include passive joint distractions and glides (grade I or II).

• Early Motion. Early motion is advocated to30
  • reduce the muscle atrophy that occurs primarily in type I fibers31–33;
  • maintain joint function;
  • prevent ligamentous “creeping”;
  • reduce the chance of arthrofibrosis or excessive scarring34–38; and
  • enhance cartilage nutrition and vascularization, thereby permitting an early recovery and enhanced comfort.33,39,40

Therapeutic exercise is the foundation of physical therapy and a fundamental component of the vast majority of interventions. Prescribed accurately, therapeutic exercise can be used to restore, maintain, and improve a patient's functional status by increasing strength, endurance, and flexibility. Research has demonstrated that joint motion stimulates the healing of torn ligaments around a joint45,46 and that early joint motion stimulates collagen bundle orientation along the lines of force, a kind of Wolff's law of ligaments.45,47 When designing an exercise program, the clinician should create exercises that are safe yet challenging, progressive, systematic, proprioceptively enriched, activity-specific, and based on evidence-based science.48 A typical exercise continuum includes a number of progressions, which includes the following48:

• Activities initially performed slowly before being progressed to a faster pace.
• The performance of familiar activities and then unfamiliar activities.
• Activities are initially performed on a stable base of support, and are then made progressively more challenging by increasing the amount of control required and with the introduction of activities that require dynamic control.
• The introduction of resistance during the movements. The initial resistance used is of low force and then incrementally increased.
• Correct performance of the activity with increasing levels of complexity.

• Medications. Pharmacologic intervention, which can play an important role in the management of the pain and inflammation associated with orthopaedic conditions is described in Chapter 9.

Tissue repair can be viewed as an adaptive life process in response to both intrinsic and extrinsic stimuli.50 Physical therapy cannot accelerate the healing process, but with correct education and supervision, it can ensure that the healing process is not delayed or disrupted and that it occurs in an optimal environment.9

The rehabilitation procedures used to assist with this repair process differ, depending on the type of tissue involved, the extent of the damage, and the stage of healing. Healing is related to the signs and symptoms present rather than the actual diagnosis. These signs and symptoms inform the clinician as to the stage of repair that the tissue is undergoing. Awareness of the various stages of healing is essential for determining the intensity of a particular intervention, if the clinician is to avoid doing any harm. Decisions to advance or change the rehabilitative process need to be based on the recognition of these signs and symptoms, and on an awareness of the time frames associated with each of the phases.51,52

Janda53 introduced the concept of the direct and indirect effects of neural input on muscle activation, and noted the influence that pain and swelling can have on direct muscle inhibition.

In addition to, and in conjunction with, the principles of PRICEMEM, electrotherapeutic and physical modalities can be used during this stage to help control pain, swelling, and muscle guarding. Heat, continuous ultrasound, and phonophoresis are introduced once the acute stage is ebbing.

During the inflammatory stage, it is also important for the patient to function as independently as possible. The aims of this phase are to avoid painful positions, improve ROM, reduce muscle atrophy through gentle isometric muscle setting, and maintain aerobic fitness.50,54,55

The criteria for advancement from this phase include adequate pain control and tissue healing, near-normal ROM, and tolerance for strengthening.4

Subacute or Intermediate Phase

Clinically, this stage is characterized by a decrease in pain and swelling and an increase in pain-free active and passive ROM (see Chapter 2). During passive ROM, the occurrence of pain is synchronous with tissue resistance.

Although the pain-free ROM may be increased in this phase, it is still not within normal limits, and stress applied to the injured structures still produces pain, although the pain experienced is lessened.56,57

Therapeutic Exercise

The various types of therapeutic exercise are described in Chapters 12, 13, 14, and 15. The role of exercise during recovery is discussed in this chapter. The various characteristics of an exercise load include the following20:

• Intensity (i.e., speed, resistance). Intensity is the rate at performing work, or the load or resistance under which the patient exercises.
• Duration (amount of time of the exercise session).
• Frequency (number of sessions per week).
• Volume of training. This is calculated by multiplying the resistance (force × distance) by the total number of repetitions performed in a specified period of time. Volume may also be calculated by adding the frequency and duration of rehabilitation or training sessions.
• Length (number of weeks or months).
• Pattern (continuous versus interval).
• Mode (e.g., running, cycling, swimming).

Progressions in the total load of exercise can be achieved by increasing the intensity, time, or frequency, or a combination of the three (see Chapters 12, 13, 14, and 15).20 During recovery from injury, it seems that the fibroblasts need to be guided so that the replaced collagen fibers are laid along the lines of stress.

Gentle movements to the area provide natural tensions for the healing tissues and help produce a stronger repair,58 so a progressive increase in movement should be encouraged. Each individual responds uniquely to exercise depending on a number of variables, including the following20:

• Genetic endowment. Each individual has a given genetic potential that will limit the extent to which the effects of physical training can be manifested. The farther an individual is from the genetic limit, the larger will be the improvement, but as the individual gets closer to the limit, less improvement will be elicited. Gender also plays an important role, as women tend to have less muscle mass and more body fat at a given training level.20
• Biological age. An individual's biological age has a greater impact than chronological age. Younger adults have a greater response to training than do older adults.59
• Training state. Individuals at lower levels of fitness will respond with a higher rate and magnitude of adaptation than when they possess higher levels of fitness.60
• Health status. During either sickness or injury, the amount of adaptive energy is reduced, along with the ability to perform at optimal intensities and volumes of work. This necessitates a reduction (or elimination) in the prescription of exercise during such times.
• Fatigue state. Fatigue limits one's ability to work at optimal intensities or durations.

Early motion exercises follow a predictable path: Passive ROM is progressed to active assistive and then to active ROM, based on tissue and patient responses. Strengthening exercises during this stage are initially restricted to submaximal isometrics (see Chapter 12). The submaximal isometrics are initially performed in the early part of the range, before being performed at multiple angles of the pain-free ROM. As ROM and joint play improve, concentric exercises (see Chapter 12) are initiated, with the resistance being increased as tolerated.

Manual Therapy

As with therapeutic exercise, manual therapy (see Chapter 10) plays an integral role in the healing process by providing controlled stresses to the healing tissues. Manual therapies during this stage include joint mobilizations (grade II) to help restore normal joint play, transverse friction massage, and gentle contract–relax techniques. It is important to emphasize to the patient that an overly aggressive approach during this stage can result in a delay or disruption in the repair process through an increase in the stimulation of the inflammatory chemical irritants and exudates.

Chronic or Advanced Phase

During this stage, pain typically is felt at the end of range with passive ROM, after the tissue resistance has been encountered (see Chapter 2). The only intervention that consistently appears beneficial across a wide spectrum of spinal and nonspinal musculoskeletal problems is the continued application of controlled stresses.

Manual Therapy

Manual techniques may be required in this stage to emphasize the restoration of joint motion and to increase the extensibility of soft tissues. Techniques to increase joint motion may include joint mobilizations (grades III–V). Techniques to increase soft-tissue extensibility include a variety of techniques including passive stretching and myofascial release (see Chapter 10).

Therapeutic Exercise

The musculoskeletal tissues respond to the controlled stresses applied to them by adaptation. This response has been described as a specific adaptation to imposed demand (SAID) (see Chapter 12).61

The application of inappropriate stresses can lead to various forms of tissue dysfunction, such as contracture, laxity, fibrosis, adhesion, diminished function, repeated structural failure, and an alteration in neurophysiologic feedback.62,63

The hierarchy for the resistive exercise progression is based on patient tolerance and response to ensure that any progress made is done in a safe and controlled fashion. The typical sequence occurs in the following order64:

• Small arc submaximal concentric/eccentric
• Full ROM submaximal concentric/eccentric
• Full ROM submaximal eccentric
• Functional/activity-specific plane submaximal concentric
• Functional ROM submaximal eccentric
• Open- and closed-kinetic chain exercises performed concentrically and then eccentrically
• Full ROM submaximal concentric isokinetic
• Full ROM submaximal eccentric isokinetic
• Functional ROM submaximal eccentric isokinetic

In the instance of chronic conditions, a slight increase or worsening of symptoms is sometimes permissible with exercise,53 because the desensitization of some of the structures may require a mechanical input via stimulation of the large A fibers (see Chapter 3). However, the increase in symptoms may also signal a retriggering of the inflammatory process.65 To help prevent these pathologic changes, Liebenson66 recommends the following:

• Patient education about how to identify and control external sources of biomechanical overload.
• Early identification of psychosocial factors of abnormal illness behavior.
• Identification and rehabilitation of the functional pathology.

What is considered to be “normal” flexibility, strength, speed, and aerobic or anaerobic endurance for most patients in rehabilitation is inadequate for those patients returning to sport.67 As skill is associated with enhanced mechanical efficiency and reduced risk of injury, skill in exercise-specific action should be established before the training load is increased.20

Return to Function

In the modern, cost-conscious health-care environment, the stage at which the patient is ready to return to full function is not often played out in the clinic. Although patient education emphasizing a slow and gradual return to activity can, to some extent, prepare the subject for this phase, reinjury, or insufficient recovery, is a real possibility.

The terms function and functional have been used extensively within the field of rehabilitation. In the context of physical therapy, function has been defined as “those activities identified by an individual as essential to support physical, social, and psychological well-being and to create a personal sense of meaningful living.”68 Functional limitations have been described as the “limitation of performance at the level of the whole organism or person…and should not be confused with diseases, disorders, conditions, or impairments involving specific tissue, organ, or system abnormalities that result in signs or symptoms.”68

Therefore, in order to restore function, the clinician must think beyond the level of impairments of specific tissues and structures resulting from injury, but instead focus on the functional limitations of the patient. Such focus requires knowledge of functional testing rather than the traditional clinical testing (e.g., range of motion, strength). Functional tasks can be designed to assess the balance, balance reach, excursion, speed and agility, endurance, strength, and power of the patient, which can then be equated with function.69 Similarly, functional progression training should involve not merely the reproduction of an activity or task by an exercise. Instead, the ultimate goal of functional training is the restoration of the patient's confidence, which implies a return to normal of the neurovascular, neurosensory, and kinesthetic systems of the body, so that the reflex performance of a movement is not deliberate, hesitant, or dyskinetic.70–72

It should be obvious that the speed and extent by which the injured tissues heal determines both the speed and the extent of the progression toward an optimum functional outcome. While it is virtually impossible to hasten the healing process, it is possible to prescribe a controlled and safe continuum, in which the patient can improve his or her functional status, without harming the healing structures.

Functional progression training, as with exercise progressions, must be designed in a sequential, step-by-step manner, beginning with simple tasks and progressing to highly coordinated tasks, with each step in the process requiring greater skill than the last. The overriding principle of functional rehabilitation is to return patients to the functional level they desire, or at which they were previously functioning.71

Ideally, the functional progression should be based on the SAID principle (see Chapter 12) in order to prepare the patient to meet the specific demands of his or her vocation, activities of daily living, or recreation. A task-oriented approach requires the clinician to understand the specific requirements of an occupation, activity, or sport. The clinician should assume that the tasks involve motions or stresses in all three planes; multiple joints, segments, or limbs; contributions from uniarticular and multiarticular muscles; and the simultaneous need for the body to move and be stable.73 Important specific considerations include the73

• common postures and movement patterns;
• amount of motion;
• speed of movement;
• nature and magnitude of forces/resistances;
• dominant directions/planes of motion;
• muscular activation patterns;
• joint-specific demands;
• symmetry or asymmetry of motion;
• unilateral or bilateral limb demands; and
• environmental demands.

Functional progressions that are specific to the lower or upper extremity are included in various chapters of this book. Functional progressions and their grading for the nonathlete are also included.74 A number of functional progressions for athletes have been devised to guide the clinician. Most of these progressions originated from postsurgical protocols, in particular, from anterior cruciate ligament reconstructions and rotator cuff surgery, which deal with various functional levels.

Rehabilitation Modalities

Clinicians have at their disposal a battery of physical agents and electrotherapeutic modalities for use in the acute phase and once the acute stage of healing has subsided. The modalities used during the acute phase involve the application of cryotherapy, electrical stimulation, pulsed ultrasound, and iontophoresis. Modalities used during the later stages of healing include thermotherapy, phonophoresis, electrical stimulation, ultrasound, iontophoresis, and diathermy (Tables 8-2 and 8-3).

At present, with the exception of cryotherapy, there is insufficient evidence to support or reject the use of modalities.75–77 However, the absence of evidence does not always mean that there is evidence of absence (of effect), and there is always the risk of rejecting therapeutic approaches that are valid.78

If modalities have a place in the clinic, it is during the acute phase of healing, when there is little the clinician can do in the form of manual techniques or therapeutic exercise. In the remodeling or functional phase, thermal modalities may be used to promote blood flow to the healing tissues and to prepare the tissues for exercise or manual techniques. However, at the earliest opportunity, the patient should be weaned away from these modalities, and the focus of the intervention should shift to the application of movement and the repeated and prolonged functional restoration of the involved structures.

Two categories of modalities are recognized:

1. Physical agents and mechanical modalities

2. Electrotherapeutic modalities

Physical Agents

• Cryotherapy. The use of ice, or cryotherapy, by itself79 or in conjunction with compression,25–27,80 has been demonstrated to be effective in minimizing the amount of exudate. Cryotherapy, which removes heat from the body, thereby decreasing the temperature of the body tissues, is the most commonly used modality for the intervention of acute musculoskeletal injuries.57,59−61 Hocutt and colleagues80 demonstrated that cryotherapy started within 36 hours of injury was statistically better than heat for complete and rapid recovery. Patients using cryotherapy within 36 hours of injury reached full activity in an average of 13.2 days compared with an average 30.4 days for those initiating cryotherapy more than 36 hours after injury. Individuals who used heat required 33.3 days for return to full activity.80

The physiologic effects of a local cold application are principally the result of vasoconstriction, reduced metabolic function,62 and reduced motor and sensory conduction velocities.63,64 These effects include the following:

• A decrease in muscle and intra-articular temperature. The decrease in muscle temperature65 and intra-articular structures66−68 occurs because of a decline in local blood flow57,59,61,69,70 and appears to be most noticeable between the temperatures of 40°C and 25°C.71 Temperatures below 25°C, which typically occur after 30 minutes of cryotherapy, actually result in an increase in blood flow (Hunting effect),71 with a consequent unfavorable increase in hemorrhage and an exaggerated acute inflammatory response.64 The reduction in muscle and intra-articular temperature is maintained for several hours after removal of the cooling agent.72 A prolonged application of cold, however, can result in a sympathetically mediated reflex vasodilation in an attempt to rewarm the area, which may actually worsen the swelling.72,73
• Local analgesia.77,79,81–85 The stages of analgesia achieved by cryotherapy are outlined in Table 8-4.80 It is worth remembering that the timing of the stages depends on the depth of penetration and the depth of the overlying adipose tissue.86 The patient should be advised as to these various stages, especially in light of the fact that the burning or aching phase occurs before the therapeutic phases.
• Decreased muscle spasm.26,77,87–89
• Decrease in edema.21,77,90
• Decrease in nerve conduction velocity (NCV).91

Several methods of applying cryotherapy have been examined in different studies. The use of ice chips in toweling has been shown to be more effective in decreasing skin temperature than ice chips in plastic bags, or cold gel packs.92,93 Findings from another study94 indicated that ice massage and ice bags are equally effective in decreasing intramuscular temperature and in maintaining the duration of temperature depression. That study also found that ice massage achieves maximal intramuscular temperature decrease sooner than the ice bag.94

Ice massage is recommended in all of the phases when any inflammation is present, but particularly in the acute phase, because of its effectiveness in reducing both pain and edema.85,94–97 Ice that has been frozen in a paper cup is applied to the area in small, circular motions for 10–15 minutes before and after activity, up to six times a day.

Cold packs applied directly to the joint area are useful in decreasing pain.84 Current recommendations are to apply ice for 20–30 minutes every 2 hours.98

The application of cold to an area is contraindicated over superficial nerves or healing wounds in patients with Raynaud disease or cold sensitivity and in areas with poor circulation or sensation.99

• Thermotherapy. Thermotherapy involves the therapeutic application of heat, which involves the transfer of thermal energy. Five types of heat transfer exist:

1. Convection occurs when a liquid or gas moves past a body part. An example of this type of heat transfer is the whirlpool.

2. Evaporation occurs when there is a change in the state of a liquid to a gas and a resultant cooling takes place. An example of this type of heat transfer occurs during spray and stretch techniques.

3. Conversion occurs when one form of energy is converted into another form. Examples of this type of heat transfer include ultrasound, shortwave diathermy, and microwave diathermy.

4. Radiation occurs when there is a transmission and absorption of electromagnetic waves.

5. Conduction occurs when heat is transferred between two objects that are in contact with each other. An example of this type of heat transfer occurs with hydrocollator heating packs.

Thermotherapy is used in the subacute and chronic stages of healing, because the deep heating of structures during the acute inflammatory stage has the potential to destroy collagen fibers and accelerate the inflammatory process,100 whereas in the later stages of healing, an increase in blood flow to the injured area is beneficial.

The physiologic effects of a local heat application include the following101–105:

• Dissipation of body heat through selective vasodilation and shunting of blood via reflexes in the microcirculation, and regional blood flow.106
• Decreased muscle spasm.83,106–108 This probably results from a decrease in neural excitability of the sensory nerves.
• Increased capillary permeability, cell metabolism, and cellular activity, all of which have the potential to increase the delivery of oxygen and chemical nutrients to the area, while decreasing venous stagnation.102,109
• Increased analgesia through hyperstimulation of the cutaneous nerve receptors.
• Increased tissue extensibility,106 which has obvious implications for the application of stretching techniques. The best results are obtained if heat is applied during the stretch and if the stretch is maintained until cooling occurs after the heat has been removed.

An applied temperature of 40°C and 45°C is considered effective for a heat intervention. Commercial hot packs, or electric heating pads, are a conductive type of superficial moist heat, and the temperature of the unit is set anywhere between 65°C and 90°C. The moist heat pack causes an increase in the local tissue temperature, reaching its highest point about 8 minutes after the application.111 The depth of penetration for traditional heating pads (and cold packs) is about 1 cm, which results in changes in the cutaneous blood vessels and the cutaneous nerve receptors.93

Wet heat produces a greater rise in local tissue temperature compared with dry heat at a similar temperature.112 However, at higher temperatures, wet heat is not tolerated as well as dry heat.

It is important to assess the patient's sensitivity to temperature, pain, and circulation status prior to the use of thermotherapy. Moist heat should not be applied to an area with decreased sensation, poor circulation, an open wound, or an acute injury.99 The application of moist heat to an area of malignancy is also contraindicated, because it can increase the temperature of the tumor and increase the rate of growth.99 Hemophiliacs are also at risk with thermotherapy because of the increased blood flow.

• Ultrasound. Ultrasound, which produces a high-frequency alternating current, is primarily used for its ability to deliver heat to deep musculoskeletal tissues such as tendon, muscle, and joint structures using ultrasonic waves. These sound waves are delivered through a transducer, which has a piezoelectric crystal, the latter of which vibrates very rapidly, converting electrical energy to acoustical energy. As the energy, which leaves the transducer in a straight line, travels further from the transducer, the waves begin to diverge. The depth of penetration of the sound waves depends on a number of factors including the absorption and scattering of the beam, the medium being used (gel or lotion), the contact quality of the transducer, the treatment surface, and the tissue type (muscle, skin, fat, etc.).113,114 Scar tissue, tendon, and ligament demonstrate the highest absorption. Tissues that demonstrate poor absorption include bone, tendinous and aponeurotic attachments of skeletal muscle, cartilaginous covering of joint surfaces, and peripheral nerves lying close to bone.115 The portion of the sound head that produces the sound wave is referred to as the effective radiating area (ERA). The ERA is always smaller than the transducer.

Clinical units typically deliver ultrasound of 0.75–3 MHz, with duty cycles ranging from 20% to 100%. The depth of penetration of the ultrasound is roughly inversely related to its frequency.116,117 A frequency of 3 MHz is more superficial, reaching a depth of approximately 2 cm, whereas 1 MHz is effective to a depth of 4 or 5 cm.118 Duty cycles less than 100% are usually termed pulsed ultrasound, whereas a 100% duty cycle is referred to as continuous ultrasound. Continuous-mode ultrasound produces a thermal effect. Pulsed ultrasound does not. The thermal effects of ultrasound are similar to those previously described for thermotherapy. The nonthermal or mechanical properties of ultrasound are less well defined but are believed to alter cellular permeability and metabolism and may be important in the promotion of wound healing by reducing edema, pain, and muscle spasms.119–122

The beam nonuniformity ratio of ultrasound is the maximal/average intensity (W/cm2) found in the ultrasound field. Each transducer produces sound waves in response to the vibration of the crystal. This vibration has different intensities at points on the transducer head, having peaks and valleys of intensity. The greater the ratio difference in the beam nonuniformity ratio, the more likely the transducer will have hot spots. Hot spots are areas of high intensity. High intensities have been shown to cause unstable cavitational effects and to retard tissue repair.122,123 Intensities of 0.1–0.3 W/cm2 are recommended for acute lesions, whereas 0.4–0.8 W/cm2 are recommended for chronic lesions.124

Treatment times for ultrasound are based on the principle of 1 minute of ultrasound per treatment head area, although account must be taken of the pulse ratio employed. The pulse ratio needs to be higher for more acute lesions (1:4) and lower for more chronic ones (1:1 or continuous).

One study125 demonstrated that to achieve a tissue temperature of 4°C, using continuous ultrasound, the following parameters and application times are necessary:

• 1 MHz at 1.5 W/cm2 for 13 minutes
• 3 MHz at 1.5 W/cm2 for 4.5 minutes

It must be remembered that the effects of ultrasound are predominantly empirical and are based on reported biophysical effects within tissue,123,126 and on anecdotal experience in clinical practice.127–129 Despite the paucity of documented evidence in terms of randomized control studies,130 many benefits have been ascribed to ultrasound. These include the following:

• Production of cellular excitation, enhancing cellular activity rather than dampening it, and enhancing the inflammatory cascade, thereby encouraging the tissues to move into their next phase.115,131–133
• Decreased swelling when applied in a pulsed format during the inflammatory stage of healing.123,124,126,134–139
• Stimulation of the active cells and a maximization of scar production activity and quality, if applied during the neurovascular phase.139–141 During the latter phase, ultrasound appears to enhance the remodeling of tissue.123,137,140
• An alteration of the parameters of ultrasound, which changes the intent of the intervention.56

• Phonophoresis. Phonophoresis is a specific type of ultrasound application in which pharmacologic agents are introduced in an attempt to drive these drugs transdermally into subcutaneous tissues.135,142–148 Theoretically, increases in cell permeability and local vasodilation may result in increased diffusion of the topical agent.135,143,144

The efficacy of phonophoresis has not been conclusively established. Some early studies have shown drug penetration as deep as 10 cm,148–150 but a more recent study has cast doubt on these findings.151 Other studies have examined the effects of phonophoresis with different corticosteroid concentrations, compared with ultrasound alone, in the intervention of various musculoskeletal conditions. Recent papers have argued that many of the commonly used cream-based preparations do not allow adequate transmission of the acoustic wave.113,114,138 Gel-based preparations appear to be superior with respect to the transmissivity of ultrasound. Consequently, gel-based corticosteroid compounds might be expected to be superior for phonophoresis applications.

Mechanical Modalities

Traction

Mechanical or manual traction has been advocated throughout the spine despite the lack of evidence for its effectiveness. Traction has been advocated to distract the zygapophyseal joint, to increase the space between the vertebrae, to enlarge the intervertebral foramina, to stretch the joint capsule and ligaments, to improve blood supply (intermittent traction), and to reduce muscle spasms and pain.152 Manual traction is usually the first form applied as it provides the clinician with information about the patient's reaction to traction. Ideally, the manual traction should be applied specifically by applying longitudinal traction to a segment while stabilizing the segments above and below using various locking techniques. The advantage of mechanical traction is that it allows the clinician to quantify the amount of force being used. The two most common modes employed with mechanical traction include the following:

• Sustained or static. This type of traction is applied continuously for a number of minutes and is recommended for patients with joint and/or nerve root irritability, those with reasonable developing neurological signs that have been associated with irritability, and those patients with severe arm pain combined with reduced neck movement toward the painful side.
• Intermittent. This type of traction is applied for short periods, with the rest period in between and as indicated for patients with an acute joint derangement, those requiring generalized joint mobilization, and pain coming from muscle spasm.

Contraindications to mechanical traction include impaired cognitive function, rheumatoid arthritis, osteoporosis, evidence of instability, claustrophobia, spinal tumors, spinal infections, spondylolisthesis, vascular compromise, and very old or young patients.

Two types of mechanical traction are described, cervical and lumbar.

• Cervical. Cervical traction is applied with the patient in sitting or supine position, although the supine position is generally preferred as it removes the weight of the patient's head. With intermittent traction, a duty cycle of either 1:1 or 3:1 is used, and the treatment time varies according to the condition being treated—5–10 minutes is recommended for acute conditions and disk protrusion and 15–30 minutes is recommended for other conditions.153–155 Weights of 25–45 lb appear necessary to produce vertebral separation with cervical traction.156 Twenty to twenty-five pounds is necessary to straighten the lordotic curvature of the cervical spine. Approximately 8–10 lb or 7–10% of the patient's body weight is recommended initially to treat disk protrusions, muscle spasm, and to elongate soft tissue in acute conditions.153–155 Less force appears to be necessary when treatment is directed to the upper cervical area.156 It is possible to apply traction more specifically by varying the angle of neck flexion153–155:

• To increase the intervertebral space at the C1–C5 levels, approximately 0–5 degrees should be used.
• To increase the intervertebral space at the C5 through C7 levels, 25–30 degrees of flexion is recommended.
• Twenty-four to thirty-five degrees of flexion is recommended for zygapophyseal joint separation.
• Zero degree of flexion is recommended for disk dysfunction.

Lumbar

The total treatment times to be used in lumbar traction are only partially research based and can range from 5 minutes to 30 minutes.157–159 The traction force necessary to cause effective vertebral separation varies (approximately 50% of the patient's body weight).157–159

• Hydrotherapy.
  • Whirlpool. A whirlpool may be used in an attempt to facilitate the resorption of effusion. A cold whirlpool is indicated in acute and subacute conditions, in which gentle exercise of the injured part is permitted. The temperature for a cold whirlpool is in the range of 50–60°F (10–16°C). A warm whirlpool is indicated in chronic conditions. During the treatment, the body part may be exercised. The temperature of a warm whirlpool is in the range of 100–110°F (39–45°C).
  • Contrast Bath. Contrast baths are an alternating cycle of warm and cold whirlpools that create a cycle of alternating vasoconstriction and vasodilation. Contrast baths are used most often in the management of extremity injuries.160,161 In a study by Myrer and colleagues,162 contrast therapy of 20 minutes' duration had no impact on the intramuscular temperature of the gastrocnemius of their subjects 1 cm below the subcutaneous fat, as measured by a microprobe.162
  • Prolotherapy. Prolotherapy, also known as “proliferation therapy,” is a relatively controversial injection-based pain management technique that may be used as an intervention for degenerative or chronic injury to ligaments, tendons, fascia, and joint capsular tissue. Prolotherapy involves the injection of a small volume of an irritant solution (e.g., dextrose 10%, sodium morrhuate, and phenol–glycerine–glucose) at multiple sites on painful ligament and tendon insertions and in adjacent joint spaces. Although prolotherapy is not administered by physical therapists, patients seen in the clinic may have received a course of prolotherapy from their physician and is thus included for completeness.

Prolotherapy is purported to allow rapid production of new collagen and cartilage through stimulation of the immune system's healing mechanism. The number of injections required per intervention are based on the type of injury. Rabago and colleagues163 reviewed data from 34 case reports and case series and two nonrandomized control trials and suggested that prolotherapy was efficacious for many musculoskeletal conditions. However, they concluded that further investigation with high-quality randomized controlled trials was required before it would be possible to determine whether or not prolotherapy was effective.

• Sclerosing Therapy. Sclerosing injections have been used on patients with various conditions, including chronic low back pain,164–166 shoulder impingement,167 tennis elbow,168 Achilles tendinosis,169,170 and patella tendinosis,171 with good results. Sclerosing therapy involves the injecting of abnormal vessels that are associated with painful tendons with a sclerosing agent to decrease pain. High-resolution color Doppler ultrasound shows intratendinous Doppler activity in patients with chronic tendinopathy. The affected area is sclerosed with vascular ingrowth. The injected chemical (e.g., Polidocanol) irritates the vascular intima to cause a vessel thrombosis. In addition, it may also sclerose the nerves adjacent to the new vessels, either directly (by destruction) or indirectly (by ischemia), which could explain the reduction in pain following the procedure.

Electrotherapeutic Modalities

• Electrical Stimulation. Historically, many clinicians have advocated electrical stimulation as a means of edema and pain reduction and to enhance an individual's functional level and independence in the acute phase.90,172–176 Electrical stimulation is traditionally used to177
  • produce a muscle contraction;
  • stimulate sensory nerves to help treat pain. For example, transcutaneous electrical nerve stimulation (TENS); and
  • create an electrical field within the tissues to stimulate or alter the healing process.

In addition to its use in the acute phase, electrical stimulation can be used in the other stages of healing for the reduction of pain and for neuromuscular reeducation.

Electrical current that passes through tissue forces nerves to depolarize. The type of nerve influenced in this way and the rate at which the fiber is depolarized will determine the physiologic and, therefore, therapeutic effect achieved.178,179 Recent reports in the literature using animal models have shown varied results, based on the type of waveform, polarity used, and frequency of intervention.180–186

The limited studies on postsurgical or acutely injured patients seem to indicate that electrical muscle stimulation is either as effective as or more effective than isometric exercises at increasing muscle strength and bulk187–191 in both atrophied192 and normal muscles.193,194

However, according to Taylor and colleagues,186 the present regimens being used (i.e., one intervention per day or three times per week) may be insufficiently aggressive to provide benefit.

• Transdermal Iontophoresis. Transdermal iontophoresis is a method by which ionic therapeutic agents are administered through the skin by the application of a low-level electrical current. Iontophoresis has proved to be valuable in the intervention of musculoskeletal disorders. Iontophoresis causes an increased penetration of drugs and other compounds into tissues by the use of an applied current through the tissue. The principle behind iontophoresis is that an electrical potential difference actively causes ions in solution to transfer according to their electrical charge. Ionized medications do not ordinarily penetrate tissues, and, if they do, it is not normally at a rate rapid enough to achieve therapeutic levels.195 This problem is overcome by providing a direct current energy source.195,196

Iontophoresis has, therefore, been used for the transdermal delivery of systemic drugs in a controlled fashion.197 The factors affecting the quality of the transdermal iontophoretic transport include pH; the intensity of the current, or current density, at the active electrode; ionic strength; concentration of drug; molecular size; and the duration of the current flow (continuous or pulse current).198–200

Iontophoresis can be performed using a wide range of chemicals (Table 8-5). If the ionic source is in an aqueous solution, it is recommended that a low concentration be used (2–4%) to aid in the dissociation.201 Although electrons flow from negative to positive, regardless of electrode size, having a larger negative pad than a positive one will help shape the direction of flow.

Current intensity is recommended to be at 5 mA or less. The duration of the treatment can vary from 10 to 20 minutes. Longer durations have been shown to produce a decrease in the skin impedance, thus increasing the likelihood of burns from an accumulation of ions under the electrodes.202 An accumulation of negative ions under the positive electrode produces hydrochloric acid. An accumulation of positive ions under the negative electrode produces sodium hydroxide.

Other complications have included prolonged erythema that resolved in 24 hours, tingling, burning, and pulling sensations that were especially apparent at the start of the current or if the amperage was turned up too rapidly. The visible erythema demonstrates the clear increase of blood flow and the influence of the iontophoresis.

Currently, research has been focused on the development of iontophoretic patches for the systemic delivery of drugs as (1) they provide the option to monitor and control the power supplied during use, (2) can detect the number of times the patch has been used, and (3) the controller can be rendered unusable to avoid abuse, once the drug is exhausted.

Extracorporal Shock Wave Therapy

High-energy extracorporeal shock waves have been used in urology for the disintegration of stone concretion for almost 15 years. For the past 10 years, this technology has emerged as a treatment modality for managing pain caused by a broad range of musculoskeletal conditions. These conditions include tendinopathies and nonunion and delayed union of fractures.203–205 Currently, the therapeutic mechanisms of shock waves in musculoskeletal problems or their specific biologic effects on the various musculoskeletal tissues (bone, cartilage, tendon, ligament) are not fully understood. 206 The extracorporeal shock wave is an acoustic wave characterized by high positive pressures of more than 1,000 bar (100 MPa), which can be developed within an extremely short rise time (10−9 seconds) and followed by a low-pressure phase of tensile stress equivalent to 100 bar (10 Mpa).207 A clinically applicable shock wave represents nothing more than a controlled explosion, producing a sonic pulse in much the same way as a fast-flying aircraft may produce a sonic boom.206 When the shock wave enters the tissue, it may be dissipated and reflected so that the kinetic energy is absorbed according to the integral structure of the tissues or structures that are exposed to the shock waves.206 However, because the duration of the shock wave is so short (3–5 microseconds) and is generated at low frequencies, no thermal effect is generated. For shock waves to be effective in the clinical situation, the maximally beneficial pulse energy must be concentrated at the point at which treatment is to be provided. There are three mechanisms by which extracorporeal shock wave therapy (ESWT) units generate the shock waves: electromagnetic, electrohydraulic, and piezoelectric. The electromagnetic and piezoelectric units tend to generate lower energy shock waves than the electrohydraulic units.208 Medically useful shock waves usually are generated through a fluid medium (water) and a coupling gel to facilitate transmission into biologic tissues. The energy flux density (ED) refers to the shock wave energy “flow” through an area perpendicular to the direction of propagation208; 1,000–2,000 shock waves of an ED from 0.01 to 0.4 mJ/mm2 are usually applied two to three times at weekly intervals.207 Pulse duration is usually fixed at 3–5 microseconds and the calculation of dose (total energy delivered) depends on the choice of energy level and the total number of shock wave impulses delivered.208 Most patients report a sharp pain sensation during the application of ESWT, necessitating a skin sensation test prior to its use.

A meta-analysis by Ogden et al.209 reported that, of various applications of ESWT on musculoskeletal conditions, the use of ESWT for treating chronic, recalcitrant heel pain syndrome was the most credible.

ESWT is contraindicated for use in patients suffering from hemophilia (because it may cause microvascular disruption) and malignancy, and ESWT should not be applied over growth plates or where exposure to lung tissue may occur (clavicle or first rib).206,208

Transcutaneous Electrical Nerve Stimulation

TENS was first introduced in the early 1950s to determine the suitability of patients with pain as candidates for the implantation of posterior (dorsal) column electrodes. TENS has since been shown to be effective in providing pain relief in the early stages of healing following surgery188,210–214 and in the remodeling phase.215–218

The percentage of patients who benefit from short-term TENS pain intervention has been reported to range from 50% to 80%, and good long-term results with TENS have been observed in 6–44% of patients.215,217,219,220

TENS units typically deliver symmetric or balanced asymmetric biphasic waves of 100- to 500-millisecond pulse duration, with zero net current to minimize skin irritation,221 and may be applied for extended periods.

Three modes of action are theorized for the efficacy of this modality (see Chapter 3):

1. Gate control mechanism. Spinal gating control through stimulation of the large, myelinated A-alpha fibers inhibits transmission of the smaller pain transmitting unmyelinated C fibers and myelinated A-delta fibers.213,222

2. Endogenous opiate control. When subjected to certain types of electrical stimulation of the sensory nerves, there may be a release of enkephalin from local sites within the central nervous system and the release of β-endorphin from the pituitary gland into the cerebrospinal fluid.221,223,224 A successful application can produce an analgesic effect that lasts for several hours.

3. Central biasing. Intense electrical stimulation, approaching a noxious level, of the smaller C or pain fibers produces a stimulation of the descending neurons.

Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBOT) is the medical use of oxygen at a level higher than atmospheric pressure, which produces an excess of oxygen in the body. This increased dissolved oxygen in the plasma has been shown to more effectively reach injured tissues than oxygen-bound hemoglobin.225 The current literature includes studies of treatment of numerous different orthopaedic conditions using HBOT, including delayed onset muscle soreness, chronic wounds, fibromyalgia, complex regional pain syndrome, migraine and cluster headaches, and edema.225 The only absolute contraindication to HBOT is untreated pneumothorax.

Aquatic Therapy

Current research shows aquatic therapy to be beneficial in the treatment of everything from orthopaedic injuries to spinal cord damage, chronic pain, cerebral palsy, multiple sclerosis, and many other conditions. Among the psychological aspects, water motivates movement because painful joints and muscles can be moved more easily and painlessly in water.

The indications for aquatic therapy include instances when partial weight-bearing ambulation is necessary, to increase range of motion, when standing balance needs to be improved, when endurance/aerobic capacity needs to be improved, or when the goal is to increase muscle strength via active-assisted, gravity-assisted, active or resisted exercise.

Contraindications to aquatic therapy include incontinence, urinary tract infections, unprotected open wounds, heat intolerance, severe epilepsy, uncontrolled diabetes, unstable blood pressure, or severe cardiac and/or pulmonary dysfunction. In general, pregnant women are quite sensitive to core temperature elevations and should therefore exercise in cool to neutral temperatures.

Physical Properties and Resisted Forces

There are several physical properties of water, which make exercising in water differ from that on land:

• Density. Although the human body is mostly water, the body's density is slightly less than that of water and averages a specific gravity of 0.974, with men averaging higher density than women. Any object with a specific gravity less than that of water will float. The buoyant values of different body parts vary according to a number of factors:
• Bone to muscle weight. Lean body mass, which includes bone, muscle, connective tissue, and organs, has a typical density near 1.1.
• The amount and distribution of fat. Fat mass, which includes both essential body fat plus fat in excess of essential needs, has a density of about 0.9.

Consequently, the human body displaces a volume of water weighing slightly more than the body, forcing the body upward by a force equal to the volume of the water displaced, as discovered by Archimedes.

• Hydrostatic pressure: Pressure is directly proportional to both the liquid density and to the immersion depth when the fluid is incompressible. Water exerts a pressure of 22.4 mm Hg/ft of water depth, which translates to 1 mm Hg/1.36 cm (0.54 inches) of water depth. Thus, a human body emerged to a depth of 48 inches is subjected to a force equal to 88.9 mm Hg, slightly greater than normal diastolic blood pressure.226 The effects of hydrostatic pressure, which is the force that aids resolution of edema in an injured body part, begin immediately on the motion, causing plastic deformation of the body over a short period. This results in a cranial displacement of blood, a rise in right atrial pressure, increase in pleural surface pressure, compression of the chest wall, and a cranial displacement of the diaphragm.
• Buoyancy: As the body is gradually immersed, water is displaced, creating the force of buoyancy. A human with specific gravity of 0.97 reaches floating equilibrium when 97% of his or her total body volume is submerged:226
  • with neck depth immersion, only about 15 lb of compressive force is exerted on the spine, hips, and knees.
  • with immersion up to the symphysis pubis, 40% of the body weight is effectively offloaded.
  • with immersion up to the umbilicus, 50% of the body weight is effectively offloaded.
  • with immersion up to the xiphoid, 60% or more (depending on whether the arms are overhead or beside the trunk) of the body weight is effectively offloaded.
• Viscosity: refers to the magnitude of internal friction specific to a fluid during motion. A limb moving relative to water is subjected to the resistive effects of the fluid called drag force and turbulence when present.226
  • Drag force: It is a factor of the shape of an object and its speed of movement. Objects that are more streamlined (minimizing the surface area at the front of the object) produce less drag force.
  • Turbulence: Under turbulent flow conditions, resistance increases as a log function of velocity.

Viscous resistance increases as more forces are exerted against it, but that resistance drops to zero almost immediately on cessation of force.

Thermodynamics

The heat capacity of water is 1,000 times greater than the equivalent volume of air. The therapeutic utility of water depends greatly on both its ability to retain heat and its ability to transfer heat energy. Heat transfer begins immediately on immersion, and as the heat capacity of the human body is less than that of water (0.83 versus 1.00), the body equilibrates faster than the water does.

Design and Special Equipment

Certain characteristics of the pool should be taken into consideration if it is to be used for rehabilitation purposes:

• The pool should not be smaller than 10′ × 12′.
• The pool should have both a shallow (1.25 m/2.5 ft) and a deep (2.5 m/5 ft plus) area to allow for standing exercises and swimming or nonstanding exercise.
• The pool bottom should be flat and the depth gradations clearly marked.

Variable temperature control for the water should be available (water that is too warm can lead to fatigue or even heat exhaustion because evaporation of perspiration is not possible in water, whereas water that is too cool can cause shivering, increase muscular tension, or produce hypothermia):

• Cold plunge tanks are often used at temperatures of 10–15°C to produce a decrease in muscle pain and speed recovery from overuse injury.
• Most public and competitive pools operate in the range of 27–29°C.
• Typical therapy pools operate in the range of 33.5–35.5°C.
• Hot tubs are usually maintained at 37.5–41°C.

Rescue tubes, inner tubes, and wet vests should be purchased to assist in floatation activities. Hand paddles and pull buoys can be used for strengthening the upper extremity. Kick boards and fins are useful for strengthening the lower extremity.

Advantages

Aquatic therapy offers a number of advantages over traditional land-borne exercises:

• The buoyancy of the water allows active exercise while providing a sense of security and causing little discomfort. Deep water running drills, using a buoyancy vest, can be used to maintain fitness during recovery from lower limb injury and as a form of cross-training to reduce impact with the aim of reducing overuse injuries.
• Early in the rehabilitation process, aquatic therapy is useful in restoring range of motion and flexibility using a combination of the water's buoyancy, resistance, and warmth.
• The buoyancy provides support. An aquatic exercise program can be designed to vary the amount of gravity loading by using buoyancy as a counterforce. Shallow water vertical exercises generally approximate closed chain exercises, albeit with reduced joint loading because of the counterforce produced by buoyancy. Deepwater exercises more generally approximate open chain system, as do horizontal exercises. Paddles and other resistive equipment tend to close the kinetic chain.
• The slow-motion effect of moving in water provides extra time to control movement and to react. Aquatic exercise protocols have been successfully used to improve balance and coordination in older individuals, who face an increased risk of falling.227
• The water provides tactile stimulation and feedback.
• The buoyancy of water can be used to provide a gradual transition from non–weight-bearing to full–weight-bearing exercises by adjusting the amount the body is submerged. For acute injuries, programs typically start at non–weight-bearing depths, limiting activity below pain onset, and then progressing in weight-bearing exercise levels as symptoms permit.
• The intensity of exercise can be controlled by manipulating the body's position or through the addition of exercise equipment. During aquatic treadmill running, oxygen consumption is three times greater at a given speed of ambulation in water than on land, thus the training effect may be achieved at a significantly slower speed than on land.228

Disadvantages

The disadvantages of aquatic therapy include:

• Cost of building and maintenance.
• Difficulty in treating patients with inherent fear of water.
• Potential adverse effects on the cardiovascular system. Because an individual immersed in water is subjected to external water pressure in a gradient, which within a relatively small depth exceeds venous pressure, blood is displaced upward to the venous and lymphatic systems, first into the thighs, then into the abdominal cavity vessels, and finally into the great vessels of the chest cavity and into the heart.226 The following cardiovascular changes can occur with immersion of the body:
  • An increase in central venous pressure.
  • An increase in pulse pressure as a result of the increased cardiac filling and decreased heart rate during thermoneutral or cool immersion.
  • An increase in central blood volume.
  • An increase in cardiac volume, cardiac output, and stroke volume.
  • A decrease in sympathetic vasoconstriction resulting in a reduction in both peripheral venous tone and systemic vascular resistance.
• Potential adverse effects on the pulmonary system. Immersion of the body to the level of the thorax causes a shifting of blood into the chest cavity and increased compression of the chest.226 The combined effect is to alter pulmonary function, increase the work of breathing, and change respiratory dynamics. However, while care must be taken with patients who have inspiratory muscle weakness due to conditions such as congestive heart failure and chronic obstructive lung disease, respiratory strengthening can also be an important aspect of high-level athletic performance.

Postsurgical Rehabilitation

Traditional interventions for postsurgical patients have involved adhering to exercise protocols designed by the surgeon performing the operation in order to limit postsurgical stress. This has led to an emphasis on interventions based solely on exercises linked to time frames, a sort of “cookbook” approach, rather than a comprehensive approach designed in conjunction with the physical therapist based on clinical findings and individual consideration.

Among the key factors that must be considered in the postsurgical rehabilitation are229

• type of surgery;
• patient's age;
• patient's physical status, including weight, and other medical conditions, such as any history of cardiovascular or peripheral vascular disease (PVD), or diabetes;
• social lifestyle of the patient;
• preoperative joint contracture or muscle atrophy;
• method of fixation;
• surrounding soft tissues involved;
• degree of correction of biomechanical alignment;
• functional and recreational goals of the patient; and
• frequency of visits during the episode of care.

These factors may influence the rate at which the patient progresses through the rehabilitation process, as well as determine the extent of functional return that can be expected in the long term.

The stages of healing described in Chapter 2 should not be viewed as distinct entities or as rigid templates but as a continuum that must be modified on the basis of clinical findings and subjective responses. For example, responses to an intervention that indicate an overly aggressive approach include

• increased area of pain;
• pain at rest that lasts longer than 2 hours after exercising230; and
• pain that alters the performance of an activity or exercise in a detrimental manner.230

Obviously, each surgical procedure is different, as is the healing capacity of each individual. In addition, each surgeon has his or her opinion as to the intensity of the postsurgical intervention. These opinions must always be respected. The point at which the tools of intervention are used following surgery may vary, and although estimated timetables are provided with each of the protocols, the intention is to provide the clinician with intervention ideas rather than a regimented timescale.

Realistic goal setting is important following surgery. Postsurgical rehabilitation goals should be based on the status of the uninvolved extremity as long as the uninvolved extremity has no deficits. For cases in which the uninvolved extremity does have deficits, the clinician should use the guidelines from expected norms. The patient should be involved in the goal-setting process when possible.

Patient/Client-Related Instruction

Patient/client-related instruction forms the cornerstone of every intervention. During the physical therapy visits, the clinician and the patient work to alter the patient's perception of the functional capabilities. Together, the patient and clinician discuss the parts of the patient's life that he or she can and cannot control and then consider how to improve those parts that can be changed. It is imperative that the clinician spends time educating the patient about his or her condition, so that the patient can fully understand the importance of his or her role in the rehabilitation process and become an educated consumer. Educating the patient about strategies to adopt in order to prevent recurrences and to self-manage his or her condition is also very important. Discussions about intervention goals must continue throughout the rehabilitative process and must be mutually acceptable.

Oftentimes, the physician relies on the physical therapist to give a broader explanation about the condition and to answer questions and concerns related to the rehabilitative process. The aim of patient education is to create independence, not dependence, and to foster an atmosphere of learning in the clinic. A detailed explanation should be given to the patient in a language that he or she can understand. This explanation should include

• the name of the structure(s) involved, the cause of the problem, and the effect of the biomechanics on the area. Whenever possible, an illustration of the offending structure should be shown to the patient. Anatomic models can be used to explain biomechanical principles in layperson's terms.
• information about tests, diagnosis, and interventions that are planned.
• the prognosis of the problem and a discussion about the patient's functional goals. An estimation of healing time is useful for the patient, so that he or she does not become frustrated at a perceived lack of progress.
• what patients can do to help themselves. This includes the allowed use of the joint or area, a brief description about the relevant stage of healing, and the vulnerability of the various structures during the pertinent healing phase. This information makes the patient aware and more cautious when performing activities of daily living, recreational activities, and the home exercise program. Emphasis should be placed on dispelling the myth of “no pain, no gain,” and patients should be encouraged to respect pain. Patients often have misconceptions about when to use heat and ice, and it is the role of the clinician to clarify such issues.
• home exercise program. Before prescribing a home exercise program, the clinician should take into consideration the time that will be needed to perform the program. In addition, the level of tolerance and motivation for exercise vary among individuals and are based on their diagnosis and stage of healing. A short series of exercises, performed more frequently during the day, should be prescribed for patients with poor endurance or when the emphasis is on functional reeducation. Longer programs, performed less frequently, are aimed at building strength or endurance. Each home exercise program needs to be individualized to meet the patient's specific needs. Although two patients may have the same diagnosis, the examination may reveal different positive findings and stages of healing, both of which may alter the intervention.

There are probably as many ways to teach as there are to learn. The clinician needs to be aware that people may have very different preferences for how, when, where, and how often to learn. It is not within the scope of this text to discuss all of the theories on learning, but an overview of the major concepts is merited.

Litzinger and Osif231 organized individuals into four main types of learners, based on instructional strategies:

1. Accommodators. This type looks for the significance of the learning experience. These learners enjoy being active participants in their learning and will ask many questions, such as, “What if?” and “Why not?”

2. Divergers. This type is motivated to discover the relevancy of a given situation and prefers to have information presented in a detailed, systematic, and reasoned manner.

3. Assimilators. This type is motivated to answer the question, “What is there to know?” These learners like accurate, organized delivery of information, and they tend to respect the knowledge of the expert. They are perhaps less instructor intensive than some other types of learners and will carefully follow prescribed exercises, provided a resource person is clearly available and able to answer questions.

4. Convergers. This type is motivated to discover the relevancy, or “how,” of a situation. The instructions given to this type of learner should be interactive, not passive.

Another way of classifying learners that is frequently used was devised by Taylor,186 who proposed that there are three common learning styles:

1. Visual. As the name suggests, the visual learner assimilates information by observation, using visual cues and information such as pictures, anatomic models, and physical demonstrations.

2. Auditory. Auditory learners prefer to learn by having things explained to them verbally.

3. Tactile. Tactile learners, who learn through touch and interaction, are the most difficult of the three groups to teach. Close supervision is required with this group until they have demonstrated to the clinician that they can perform the exercises correctly and independently. Proprioceptive neuromuscular facilitation techniques, with the emphasis on physical and tactile cues, often work well with this group.

A patient's learning style can be identified by asking how he or she prefers to learn. Some patients will prefer a simple handout with pictures and instructions; others will prefer to see the exercises demonstrated and then be supervised while they perform the exercises. Some may want to know why they are doing the exercises, which muscles are involved, why they are doing three sets of a particular exercise, and so on. Others will require less explanation.

If the clinician is unsure about the patient's learning style, it is recommended that each exercise first be demonstrated by the clinician and then by the patient. The rationale and purpose behind each of the exercises must be given, as well as the frequency and intensity expected.

Compliance is vitally important in the healing process. Compliance can be defined as engaging in behavior as instructed or prescribed.232 Another term “adherence,” which can be defined as choosing to engage in behaviors, is similar in that both vary from patient to patient and both are related to motivation. Motivation, a psychological feature that drives an organism toward a desired goal, is considered vital to maintaining behavior. Motivation has been classified as either intrinsic (internal) or extrinsic (external). A number of motivational theories have been proposed (Table 8-6).

Anecdotally, unmotivated patients may progress more slowly. Much literature has conceptualized or reported poor motivation in rehabilitation as secondary to patient-related factors, including depression, apathy, cognitive impairment, low self-efficacy (e.g., low confidence in one's ability to successfully rehabilitate), fatigue, and personality factors.233 Various studies have found that average compliance with medication regimens occurs only in 50–60% of patients, and compliance with physical therapy programs is approximately 40%.234 Other reports have found that compliance was decreased if the physical therapists did not provide their patients with positive feedback.235

Several considerations should be made to increase compliance:

• The patient's age—older individuals tend to adhere to exercise programs more than younger individuals.236
• The patient's marital status—singles tend to have lower rates of adherence to physical activity/exercise than married couples.237
• The patient's education—individuals with high levels of education show more compliance to exercise programs than those who are uneducated.237
• The patient's gender—males report greater levels of total and vigorous activity than females.237
• The patient's biomedical status—poorer health tends to lead to decreased adherence.238
• The patient's socioeconomic status—an individual's income bracket tends to influence the ability to access medical care, as well as exercise equipment and venues.239–241
• The patient's ethnicity—Caucasians appear to participate in more physical activities than other racial or ethnic groups, regardless of age.237

Finally, a number of factors have been outlined to improve compliance; including242–244

• involving the patient in the intervention planning and goal setting;
• realistic goal setting for both short- and long-term goals;
• promoting high expectations regarding final outcome;
• promoting perceived benefits;
• projecting a positive attitude;
• providing clear instructions and demonstrations with appropriate feedback;
• keeping the exercises pain free or with a low level of pain; and
• encouraging patient problem solving.

Health Promotion, Wellness, and Physical Fitness

In 1996, the Surgeon General's report on physical activity and health highlighted the importance of engaging in an active lifestyle to prevent the insidious onset of chronic disease and illness.245 Healthy People 2010 established goals for promoting a healthy lifestyle for individuals in the United States.246

The World Health Organization has defined health promotion as “the process of enabling people to increase control over their health and its determinants, and thereby improve their health.”*

The National Wellness Institute has delineated six components of wellness † :

• Social. This includes contributing to one's environment and community and emphasizing the interdependence between others and nature.
• Occupational. This includes satisfaction and enriching life through work.
• Spiritual. This includes an appreciation of the depth of an expansive life and having meaning in one's life.
• Physical. This includes awareness of the need for regular physical activity, good diet and nutrition, and avoiding habits that are harmful to wellness.
• Intellectual. This includes being able to solve problems, expand knowledge and skills, and have an openness to new ideas.
• Emotional. This includes awareness and acceptance of one's feelings and thinking of oneself positively.

Physical therapists serve as major providers of health promotion, wellness, and fitness by making patients and clients more aware of lifestyle changes, particularly in the areas of physical activity, lifelong health promotion, and creating an environment that supports health practices leading to a healthy lifestyle.247 Evidence exists that when healthcare professionals counsel patients about risk reduction, those patients are more likely to change poor health habits, thus enhancing a healthier lifestyle.**

The effects of physical activity and exercise on various physiological and psychological parameters across the lifespan for use of exercise prescriptions support their role in preventing disease and improving function and health. This is particularly relevant in promoting mobility and dependence of the elderly, the older old, and the frail elderly.247

*Available at http://w3.whosea.org/EN/Section1174/Section1458/Section2057.htm, accessed September 2005.

†Available at www.nationalwellness.org/index.php?id=166&id_tier=81, accessed September 2005.

**Available at www.healthwellness.org/archive/research/study5.htm, accessed November 2004.

• 1. What are the three components that comprise the intervention?

• 2. What does the pneumonic PRICEMEM stand for?

• 3. Give five therapeutic benefits of the application of manual therapy in the early stages of healing.

• 4. With passive mobility testing, which stage of healing is indicated when pain is reported before tissue resistance is felt by the clinician?

• 5. What are the intervention goals during the inflammatory stage of healing?

Answers