Surface Electrical Stimulation of Trunk Musculature during Wheelchair Propulsion

Alicia M. Koontz, PhD, RET^1,2, Yu-Sheng Yang, PhD^1,2, Ronald J.Triolo PhD³, Jennifer Mercer, BS^1,2, Shirley Fitzgerald, PhD^1,2, Rory A. Cooper, PhD^1,2, and Michael L. Boninger MD^1,2

Human Engineering Research Laboratories, Highland Drive VA Medical Center, Pittsburgh, PA¹

Dept. of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA²

Cleveland FES Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH³

ABSTRACT:

The purpose of this study was to examine how surface functional electrical stimulation (FES) of trunk musculature influences wheelchair propulsion biomechanics and metabolic responses. Eleven wheelchair users with spinal cord injury (SCI) pushed on a dynamometer at a target speed of 1.34 m/s for three five-minute trials. One of three stimulation levels (HIGH, LOW and OFF) was randomly applied to the abdominal and back muscle groups with a commercial FES device. Results showed that participants with HIGH stimulation produced higher propulsion power output (p=0.02) and increased their gross mechanical efficiency (GME) (p=0.05). Using FES on trunk muscles may enable wheelchair users with SCI to more easily and efficiently transfer power from their upper body muscles to the wheelchair.

KEYWORDS:

Kinematics, kinetics, metabolic analysis, biomechanics, mechanical efficiency