Electromyographic analysis of gait in eight patients who had had a
modified Van Nes rotationplasty was performed to compare the activity of
the flexors and extensors of the ankle on the side of the operation with
that of the flexors and extensors of the knee on the normal, contralateral
side. The resemblance in the activity of the extensors was more pronounced
than that of the flexors. In three patients, the angle of flexion of the
knee throughout the gait cycle was the same on the side of the
rotationplasty as on the normal side. There was more symmetry in the swing
phase than has been reported for patients who have had an above-the-knee
amputation. The strength of the dorsiflexors of the ankle on the side of
the rotationplasty was 68 percent and that of the flexors was 71 per cent
when compared with that of the muscles of the normal ankle.