The purpose of this study was to analyze the effect of lengthening of
the medial hamstrings on the gait of patients who had spastic cerebral
palsy. Thirty-one patients had preoperative and postoperative gait
analyses. Standard parameters, such as velocity, cadence, and stride
length, were evaluated, as were motion graphs of the hip, knee, and ankle.
There was little difference between the preoperative and postoperative mean
values for velocity, cadence, and stride length, which were expressed as
percentages of normal for the patient's age. The contours of the
postoperative motion graphs of the knees changed very little compared with
those of the preoperative graphs; when a graph showed restricted motion
preoperatively, it did so postoperatively. Although extension of the knee
in stance phase improved postoperatively, the improvement was accompanied
by decreased flexion of the knee during swing phase. When spasticity of
both the hamstrings and the quadriceps was noted on the preoperative
electromyogram, motion of the knee in the sagittal plane was markedly
restricted.