Peak Physiological Responses to Functional Electrical Stimulation During Over Ground and Treadmill Ambulation

0185 Introduction: Physiological measurements during Functional Electrical Stimulation (FES) ambulation have been limited to overground testing. Thus, responses to over ground FES ambulation in comparison to those from FES treadmill walking have not been documented. Purpose: The purpose of this study was to compare the peak physiological responses to FES ambulation over ground with ambulation on the treadmill. Methods: Two subjects with neurologically complete paraplegia (T7 & T3) participated as subjects in this study. Each subject participated in treadmill and overground walking in randomized order. Each test was completed on separate days with one week between. Peak oxygen uptake (VO2) was determined by a discontinuous protocol using the ExoStim FES device (Neopraxis, AU). Metabolic measures were collected continuously using an open circuit spirometry as subjects performed a series of discontinuous bouts with increasing pace. Each bout consisted of three minutes, followed by 15 minutes of seated recovery. Results: Peak oxygen consumption was greater on the treadmill (36.3 ml/kg/min and 24.2 ml/kg/min) than overground (21.41 ml/kg/min and 21.22 ml/kg/min) for the two subjects, respectively. Velocity of ambulation was greater on the treadmill (0.18 m/sec. and 0.22 m/sec) than overground (0.09 m/sec. and 0.13 m/sec) for the two subjects, respectively. Gait efficiency was 16% and 41% greater on the treadmill for the two subjects, respectively. Conclusion: The results of this limited preliminary study (n = 2) suggest that FES treadmill walking may provide a mode of training that allows greater peak physiological responses, greater walking velocity, and enhanced gait efficiency compared with FES overground ambulation.