Sitting posture and prevention of pressure ulcers.

The aim of this study was to gain insight about the influence of body posture on the pressure at the seat surface and to establish to what extent different seat cushions designed for incontinent patients reduce maximum pressures. Pressures were measured for 56 healthy volunteers in eight postures using four cushions. The posture in which the lowest maximum pressure was measured was the sitting-back posture with the lower legs on a rest. If the seat could not be tilted back, the maximum pressure in the upright sitting posture with the feet on the ground was significantly lower than sitting upright with the legs supported on a rest. Sliding down and slouching caused the highest maximum pressure. Regular checking of the posture and using positioning cushions should form part of any pressure-ulcer prevention protocol. The four selected cushions each have different pressure-reducing effects. A thick air cushion (Repose) has the lowest maximum pressure and is significantly better than the other cushions at reducing the high pressure when slouching or sliding down.