Improvement of hemiplegic gait with single channel surface stimulation

A study was undertaken to explore the patterns of abnormal motor control in a sample of chronic hemiplegic subjects and to relate these to response to stimulation. Six of the 16 hemiplegic subjects studied had tibialis anterior activation modulation within the normal range, whereas none of the patients studied had normal calf activity. Patients who are unable to activate their calf during push-off may benefit from using calf stimulation in addition to, or instead of, stimulation of the common peroneal nerve during swing phase. If, as seems possible, stimulation causes inhibition of the antagonist muscles through the Ia interneurones then patients who experience premature calf activation may benefit from an extension of stimulation period into the early stance phase and patients who experience coactivation of the calf and anterior tibial muscles during swing phase should respond particularly well to common peroneal stimulation during this period. Timing of stimulation and selection of appropriate groups of muscles may improve the response to stimulation during walking. Until all subjects have completed the study, i.e. used the stimulator for three months, it will not be possible to know whether categories of abnormal muscle activation patterns can be used to predict response to stimulation