Pedal forces produced during neuromuscular electrical stimulation cycling in paraplegics

This study investigated forces applied to the pedal of a cycle ergometer by paraplegic subjects undergoing neuromuscular electrical-stimulation-induced leg exercise. The patterns of force application were compared with those of able-bodied subjects cycling under voluntary muscle control in order to investigate the effectiveness of the muscle stimulation parameters. Results show that paraplegic subjects applied significantly larger peak forces than the able-bodied subjects because of the short duration of neuromuscular stimulation. Able-bodied subjects were able to achieve the same average workload by applying smaller forces over a greater percentage of each crank revolution. It is suggested that the large forces produced by paraplegic subjects contribute to the low efficiency reported by previous studies, and that increasing the range of angles over which muscles are stimulated may provide a means to increase the efficiency of cycling for paraplegic individuals.