Biomechanical and physiological evaluation of FES-activated paraplegic patients

Four paraplegic patients with traumatic upper motor neuron lesions at the spinal levels between D5 and D12 were activated by functional electrical stimulation (FES) and evaluated biomechanically and physiologically. After a training program aimed at strengthening the muscles of the lower legs, the patients were able to stand up, maintain the standing position, and walk for short distances while being supported. Biomechanical evaluation included weight bearing on the patients' own legs during standing as measured on a force platform and analysis of the time-distance parameters of the stride during walking as measured on a walkway. Physiological evaluation included heart rate and oxygen consumption at rest, when activated by FES in the sitting position, during standing, and during walking. The results obtained indicate that while significant standing and walking performances are achieved, the corresponding physical effort can reach relatively high levels requiring the support of anaerobic energy sources. The practical implications of these results are discussed.