Positioning in Wheelchair Bound Patients

The choice of the most suitable chair as well as the improvement of the patient's positioning on this wheelchair is important to limit the discomfort, to prevent the risks of bedsores, the pains related to prolonged sitting and finally to support the interaction of the patient with its environment. The goal of this prospective, longitudinale, monocentric study is to evaluate the impact of standardized positioning in wheelchair-bound patients at risk of slipping. The main questions on the positioning actions are: * their actions impact of positioning actions on shear forces * their impact on sliding in the chair * their impact on the feeling of discomfort in the chair * their impact on the caregivers' feelings about the patient's difficulties (eating, transfers, sliding) Participation in this study will involve an increase in the number of transfers required for shear sheet placement and removal, as well as the time required for ischial measurement and the time to complete the (Tool for Assessing Wheelchair disComfort) TAWC questionnaire.