Guidelines for a wheelchair ergonomic adaptation based on dynamometry and surface electromyography

Abstract

The aim of this study was to define design guidelines for an ergonomic adaptation in wheelchairs based on the upper limbs myoelectric activity evaluation of an experient manual wheelchair user, in flat and inclined grounds (ramp). The wheelchair use activity was carried out in a pre-established route that involved flat and inclined grounds (ascending). The data collection procedures were: socio-demographic questionnaire, hand grip dynamometry and surface electromyography. Therefore, the results found indicate, specifically, greater activity in the Flexor Digitorum Superficialis muscle groups bilaterally, which are the muscle groups responsible for assisting the manual grip on the wheel rim. In addition to this, there was a decrease in Medium Frequency values associated with an increase in the muscle use percentage, which may represent fatigue and inadequate physiological recovery of the muscle groups studied and may lead to severe musculoskeletal disorders. From the analysis of the physiological and biomechanical data, it was possible to identify biomechanical factors that may represent risks to the health of the wheelchair user, thus, design guidelines were suggested for an ergonomic adaptation that can reduce physical effort, mainly on inclined ground, aiming, specifically, to reduce the Flexor Digitorum Superficialis fatigue and increase the propulsion efficiency.