Velocity of gait will alter dynamic joint ranges
Timing of motion is crucial
If patient has minimal knee flexion (e.g. 15 degrees) at pre-swing and rapid knee flexion occurs
only when limb is unloaded (during swing phase), although patient may have correct range of knee motion the gait will be affected by the incorrect PHASING of the knee flexion.
A gait cycle consists of a period of stance (60%) and a period of swing (40%)
Stance phase is subdivided into 2 periods of DOUBLE SUPPORT (20% = 2 x 10%)
and 1 period SINGLE SUPPORT (40%)
Proportion of time spent in each will vary with velocity
Footwear influences stride length
Gait does not require full joint range or full muscle power
"There is a excess capacity of both"
Hip abductors only require 40% of full strength for the patient to walk without a limp
Full knee joint range of motion is 140 degrees but only 60 degrees of motion are needed for an efficient gait pattern.