WALKING WHEN UTILIZING A SENSORY FEEDBACK-SYSTEM AND AN ELECTRICAL MUSCLE STIMULATION GAIT ORTHOSIS

Electrical muscle stimulators (EMS) have been combined with a reciproc ating gait orthosis (RGO) to produce an EMS-RGO system for constant ve locity ambulation exercise in a spinal cord injured (SCI) individual. The objective of this study is to evaluate an auditory feedback system (AFS) used by the SCI subject when ambulating with the EMS-RGO. Three different types of auditory signals (M = metronome alone MSL = metron ome plus stride length information and NONE = no auditory feedback) we re examined al three different constant walking velocities (WV1 = 0.64 kph, WV2 = 1.22 kph, and WV3 = 1.80 kph). The experimental design was 3 X 3 full factorial with repeated measures, and the dependent variab le was the absolute error (AE) of walking distance (absolute value of the distance the subject walked in one minute subtracted from the targ et distance). A block diagram and circuit schematic of the AFS is prov ided. The results indicate that at I WI there is no significant differ ence of AE among the three auditory conditions (M, MSL and NONE). At W V2, the AE for the NONE auditory condition is significantly greater th an the AE for M and MSL (p <0.05). Af WV3, the AE for the NONE auditor y condition is significantly less than the AE for M and MSL (p <0.05). Finally, there was no significant difference in AE between both the M and MSL auditory conditions at any of the three walking velocities. T his study indicates that an adequate sensory feedback system for const ant velocity control of ambulation in this SCI subject consists of met ronome only auditory feedback. Since there is some complexity in deter mining when the NONE condition should be utilized in progressive veloc ity walking, it is preferable to retain metronome alone auditory feedb ack for all walking velocities.