Design and Fabrication of an Instrumented Handrim to Measure the Kinetic and Kinematic Information by the Hand of User for 3D Analysis of Manual Wheelchair Propulsion Dynamics

The repetitious nature of propelling a wheelchair has been associated with the high incidence of injury among manual wheelchairusers (mwus), mainly in the shoulder, elbow and wrist. recent literature has found a link between handrim biomechanics and risk ofinjury to the upper extremity. the valid measurement of three dimensional net joint forces and torques, however, can lead to a betterunderstanding of the mechanisms of injury, the development of prevention techniques, and the reduction of serious injuries to thejoints. in this project, an instrumented wheel system was developed to measure the applied loads dynamically by the hand of the userand the angular position of the wheelchair user’s hand on the handrim during the propulsion phase. the system is composed of anexperimental six axis load cell, and a wireless eight channel data logger mounted on a wheel hub. the angular position of the wheel ismeasured by an absolute magnetic encoder. the angular position of the wheelchair user’s hand on the handrim during the propulsionphase or point of force application (pfa) is calculated by means of a new experimental method using 36 pairs of infrared emitter/receiver diodes mounted around the handrim. in this regard, the observed data extracted from an inexperienced able bodied subjectpushed a wheelchair with the instrumented handrim are presented to show the output behavior of the instrumented handrim. therecorded forces and torques were in agreement with previously reported magnitudes. however, this paper can provide readers withsome technical insights into possible solutions for measuring the manual wheelchair propulsion biomechanical data.