The importance of voluntary exercise and sensory input in rehabilitation training after spinal cord injury (SCI) or cerebrovascular disease has been demonstrated by recent studies. However, the voluntary exercise is an impossible task for severe paraplegic and hemiplegic patients who cannot move their lower limbs by themselves. The purpose of this study is to verify whether these patients can perform a new voluntary exercise by using a robot suit which generates walking motion in place of the wearer's paralyzed muscles by detecting their voluntary bioelectrical signals. Two severe SCI patients who can barely produce neuromuscular activation but cannot move their lower limb participated in this study. Experimental results demonstrated that the robot suit was able to detect their voluntary neuromuscular activities via bioelectrical signals and provide stepping and walking motion having appropriate temporal relationship with the voluntary activities. In addition, the proposed voluntary exercise using the robot suit can significantly promote neuromuscular activities of the target muscles more than passive exercise.
