Posture Estimation Using Surface Electromyography during Wheelchair Hand-Rim Operations

Abstract

This study examined competitive wheelchairs that facilitate sports participation. They can be moved straight ahead using only one arm. Our designed and developed competitive wheel-chairs have a dual hand-rim system. Their two hand-rims, attached to a drive wheel on one side, can be operated simultaneously for straight-ahead movement. Specifically, based on integrated electromyography (iEMG) data calculated from surface electromyography (sEMG), we examined the wheelchair loading characteristics, posture estimation, and effects on body posture during one-arm propulsion movement. The first experiment yielded insights into arm and shoulder-joint muscle activation from iEMG results obtained for two-hand propulsion and dual hand-rim system propulsion. Results suggest that muscle activation of one arm can produce equal propulsive force to that produced by two arms. The second experiment estimated the movement posture from iEMG during one-arm wheelchair propulsion. The external oblique abdominis is particularly important for one-arm wheelchair propulsion. The iEMG posture estimation validity was verified based on changes in the user body axis and seat pressure distribution. In conclusion, as confirmed by iEMG, which is useful to estimate posture during movement, one-arm wheelchair use requires different muscle activation sites and posture than when using two arms.

Influence of a Hybrid Manual–Electric Wheelchair Propulsion System on the User’s Muscular Effort

“…The values of the moments of resistance selected in the study have been estimated experimentally [35] and correspond to the resistance to motion occurring when riding a wheelchair on an even hard surface inside a building (m = 8.14 Nm), on pavements in an urban area contaminated with loose sand (m = 9.67 Nm) and approaching a paved hill with a slope of 4° (m = 11.1 Nm). The research fits into the modern trend of designing machines and devices using the analysis of EMG signals of the upper limb muscles, and the recorded values of this signal are similar to the results obtained by other researchers [37][38][39].…”