Correlation of static to dynamic measures of lower extremity range of motion in cerebral palsy and control populations

The question addressed in this study was whether static measurements of hip, knee, and ankle range of motion correlate to dynamic measurements of hip and knee function during gait. Range-of-motion measures of the lower extremities taken during physical examination (static variables) were recorded on 80 adolescents with cerebral palsy and 30 adolescent normal controls. Kinematic measurements collected during gait analysis (dynamic variables) were recorded on the same patients and controls. Results indicated no correlation greater than r = 0.50 (R-2 < 0.25) between any static and dynamic variable for either group-cerebral palsy patients or controls. The lack of good correlation of these measures indicates static physical examination variables such as popliteal angle and straight-leg raise are not good predictors of dynamic gait, such as knee-extension and hip-flexion variables measured during ambulation in controls or cerebral palsy populations.