Twenty-three ambulatory children with spastic diplegic cerebral palsy
were evaluated clinically and by electromyography before and after
hip-muscle surgery. The stretch tests originally designed to distinguish
specific muscle tightness and spasticity were found to be non-specific when
tested by electromyography. Ambulatory electromyograms using needle
electrodes and telemetry generally showed decreased activity in the
released muscles and, on occasion, changes in activity in muscles not
operated on. These unanticipated changes after release may explain some of
the unpredictability of results of such procedures in cerebral palsy.