The major requirements for successful walking include:1
- Support of body mass by the lower extremities.
- Production of a locomotor rhythm—the stretch reflex and the extensor thrust.2 The stretch reflex is involved in the extremes of joint motion, while the extensor thrust may facilitate the extensor muscles of the lower extremity during weight bearing.3
- Dynamic balance control of the moving body.
- Propulsion of the body in the intended direction.
- Adaptability of locomotor responses to changing task and environmental demands.
A number of parameters are used to describe gait (Table 7–1).
Table 7-1. Gait Parameters ||Download (.pdf)
Table 7-1. Gait Parameters
|Step length: measured as the distance between the same point of one foot on successive footprints (ipsilateral to the contralateral foot fall).|
|Stride length: the distance between successive points of foot-to-floor contact of the same foot. A stride is one full lower extremity cycle. The average stride length for normal individuals is 1.41 m.a|
- Two step lengths added together make the stride length.
- Men typically have longer stride lengths than women.
|Typically, the stride length does not vary more than a couple of inches between tall and short individuals. Stride length decreases with age, pain, disease, and fatigue.b It also decreases as the speed of gait increases.c A decrease in 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.|
|Cadence: the number of steps taken per unit of time (steps/min) = velocity (m/s) × 120/stride length (m). Normal cadence is between 90 and 120 steps/min, with an average of 113 steps/min.d,e The cadence of women is usually 6-9 steps/min slower than that of men.f Cadence is also affected by age, with cadence decreasing from the age of 4 to the age of 7, and then again in advancing years.|
|Velocity (m/s) = cadence (steps/min) × stride length (m)/120. Normal free gait velocity on a smooth and level surface averages about 82 m/min for adults, with men being about 5% faster than women. Walking velocity declines with age at a rate of 3%-11% in healthy adults > 60 years old.a|