Geometrical analysis of hip and knee joint mobility in cerebral palsied children

The present investigation attempted to define a geometrical hexagon model for representing the sagittal range of motion (ROM) of hip and knee joint. The effect of both monoarticular and biarticular muscles on joint mobility in children with spastic cerebral palsy (SCP) were analyzed by this geometrical method. Photographic analysis was used to measure hip and knee joint angle at six different boundary positions. The ROM in normal children indicated age dependent reduction of maximal hip flexion and shortening of hamstring and rectus femoris muscles. A number of SCP children showed greater reduction of both hip flexion and extension and shortening of hamstring and rectus femoris muscles, whereas the ROM of knee joint was similar to that in normal children. The deteriorated hip joint mobility seems to be associated with shortening of muscle due to their intrinsic spasticity. The impaired ROM was more noticeable in SCP non-ambulator child than in independent ambulator. Thus, more extended range and frequent opportunity of joint motion may play an important role in improving the joint mobility in this patient group.