Adaptations in gait resulting from unilateral ischaemic block of the leg.

The purpose of this study was to develop a major temporary perturbation to the peripheral neuromuscular system and to quantify the motor adaptations on the first gait strides taken after the perturbation becomes effective. A unilateral ischaemic block to the leg was induced by a cuff inflated to 200 mmHg; sensory block was evident after 15-20 min and total motor block after about 30 min. Electromyographs from seven muscles on each limb were recorded for the first 16s after walking commenced and were compared with electromyographs from cadence-matched strides recorded 30 min after the cuff was removed. Ensemble-averaged profiles of the ischaemic and control trials from six subjects showed that almost half of the non-ischaemic muscles (4 on the ischaemic limb and 7 on the intact limb) had significantly different profiles. Only two muscles showed consistent changes for all six subjects (gastrocnemius and rectus femoris of the intact limb).