Investigation of Optimization of Load-bearing Mechanism in Passive Support Wear Reducing Lumbar Load

Abstract

Low back pain is one of the most major reasons for caregiving workers to leave their jobs. It is caused by a mechanical load acting on the muscles and the spine in the lumbar part. This paper presents a study aiming to develop a passive support wear that reduces the load on the lumbar part during a nursing care operation. In particular, the influence of the antagonism of the abdominal muscles is focused on in this paper to understand the mechanical effect of the support mechanism which is to be optimized to provide a support force from the abdominal side to minimize the compressive load on the lumbar spine. A rigid body model taking account of the muscular force of the abdominal muscles, the erector spinae, the support force is analytically examined to investigate the design requirements. It has been confirmed that the load on the lumbar spine increases due to the antagonism effect.