Experimental Platform to Assess the Weight Relief Lifting and Sitting Pivot Transfer Movements

Several times per day, manual wheelchair (MW) users perform weight relief lifting or sitting pivot transfer movements using only their upper limbs. These motions generate significant articular constraints that could lead to musculo-skeletal disorders. The geometry of the hardware configurations of manual wheelchairs influence the movements produced by these MW users. To evaluate this influence, it was necessary to design an instrumented and adjustable experimental platform that would allow the articular efforts of the weight relief lifting and sitting pivot transfer movements to be estimated. The experimental platform that we have developed is composed of 5 adjustable modules: 2 seat modules, 2 armrest modules, and 1 footrest module. These modules are instrumented to allow the effort exerted by the subjects on their environment to be measured, while a motion capture system records the position of reflective markers positioned on the subject. The measured data, coupled with kinematic, anthropometric and dynamic models, make it possible to estimate the articular effort. The results reported in the literature confirm our results, thus validating our method and our instrumentation.