Effect of Locomotor Training on Exhaustion of Leg Muscle Activity in Chronic Complete Spinal Cord Injury.

The aim of this study was to evaluate the effect of a continuous locomotor training on leg muscle electromyographic (EMG) exhaustion during assisted stepping movements in a patient with motor complete spinal cord injury (SCI). EMG exhaustion and loss of potentials starts to develop in untrained patients at ∼6 months after injury. In the trained patient examined in this study, exhaustion was also observed but occurred with a delay of several months. In contrast to an untrained patient, no more EMG exhaustion was observed in the very chronic stage. At this time (12 years after injury) a basic locomotor pattern of leg muscle activity of reduced amplitude could still be elicited, but it was resistant to exhaustion and unchanged in amplitude after 12 min of assisted stepping. It is suggested that fatigue-resistant motor units prevail at this stage and can still be activated during stepping as a result of the training.