Backrest shape affects head-neck alignment and seated pressure

Abstract

Unstable back support against gravity results in a forward head posture and contributes to buttocks pressure ulcers. However, the association between these health problems and a wheelchair backrest is unclear. Our newly developed wheelchair (N-WC) supports the back of the pelvis and thorax from obliquely underneath. The purpose of this study was to investigate the effect of different backrest shapes on head-neck alignment and seated pressure. Data from 28 healthy subjects were analyzed. Outcome measures were head-neck alignment angles, support angles of the backrest, and pressure distributions on the supporting surfaces. Compared with a typical wheelchair that has a flat backrest, the seat pressure decreased and the center of pressure was located in the middle of both the seat and backrest in the N-WC. Moreover, the head-neck alignment when seated in the N-WC was upright. These results highlight the importance of the shape of the wheelchair backrest.