Gait electromyograms were obtained before and after tendon transfer,
lengthening, or release in twenty-seven hemiplegic patients with equinus or
equinovarus deformities. Abnormal patterns of muscle activity almost always
were present preoperatively in the gastrocnemius, soleus, tibialis
posterior, flexor hallucis longus, flexor digitorum longus, peroneus
brevis, and tibialis anterior muscles in these patients. The surgical
procedures to correct the foot deformities altered the gross patterns of
activity of most of the muscles operated on by very little. Of particular
importance to the surgeon was the finding that the pattern of activity of
the muscles whose tendon was transferred, lengthened, or released was not
altered after operation. This finding makes the preoperative gait
electromyogram a useful means of determining the appropriate surgical plan,
since it is an indication of the type of muscle activity to expect
postoperatively.