Absract - The gait patterns
of eighteen patients who had had a single infarct due to obstruction of the
middle cerebral artery were evaluated within one week after the patients had
resumed independent walking and before a gait rehabilitation program had been
initiated. Gait was analyzed with use of motion analysis, force-plate recordings,
and dynamic surface electromyographic studies of the muscles of the lower extremities.
The patterns of motion of the lower extremity on the hemiplegic side had a stronger
association with the clinical severity of muscle weakness than with the degree
of spasticity, balance control, or phasic muscle activity. There was a delay
in the initiation of flexion of the hip during the pre-swing phase, and flexion
of the hip and knee as well as dorsiflexion of the ankle progressed only slightly
during the swing phase. During the stance phase, there was decreased extension
of the hip that was related to decreased muscle effort and a coupling between
flexion of the knee and dorsiflexion of the ankle. The abnormal patterns of
motion altered the velocity, the length of the stride, the cadence, and all
phases of the gait cycle. The duration of the pre-swing phase was prolonged
for the patients who had the slowest gait velocities.
There also were abnormal movements of the upper extremity, the trunk, the pelvis,
and the lower extremity on the unaffected side in an effort to compensate for
the decreased velocity on the hemiplegic side. As velocity improved, these abnormal
movements decreased. Therefore, the goal of therapy should be to improve muscle
strength and coordination on the hemiplegic side, especially during the pre-swing
phase.