Development of a Simple Supporter for Reducing Lower Back Exertion

Abstract

Seventy-seven percent of care givers and sixty-four percent of nurses are reported to experience back pain. No clinical device simply yet effectively reduces loads placed on the lower back. In this research, we report on a prototype device developed for practical use that reduces the load on the lower back. The device was designed in a simple structure for use in a deep forward leaning posture at bedsides. This paper discusses the theoretical analysis based on a mechanical model, motion analysis by measuring joint angle variations in typical nursing movements (e.g. transfer to and from the wheelchair and bedside), and the evaluation of the exertion encountered in nursing from EMG signals of the erector spinae when loads are applied. In addition, the device was tested to evaluate its potential restrictions to daily activities, i.e. sitting on a chair and crouching to pick up items on the floor. The results showed that the device does not constrain body movement and that the required exertion of subjects to support a large load is substantially reduced by use of the device, especially in the deep forward leaning posture as targeted.