Development of hip protector with a hole based on biomechanical evaluation

Abstract

The present paper is concerned with the development of a hip protector with a circular hole in the center to prevent hip fracture by fall. Firstly, we performed fall simulations by use of an elderly Japanese female model of a rigid whole body with a detailed finite element thigh model. The simulation showed that the hole in a hip protector significantly reduced impact, and that a protector with a hole of 50 mm diameter gave the minimum impact load in most cases. It also showed that thicker protectors and protectors of stiffer materials were more effective for hip fracture prevention. The effects of a protector offset from reference position, vacancies under the hole, and the shortening of protector length on the reduction ratio of impact were elucidated in detail. Secondly, based on the design guide suggested by the simulations, we developed a weight-drop test apparatus and performed experiments to examine the simulation results. It is ascertained that the hip protector with a hole of 50 mm diameter has excellent performance for hip fracture prevention.

Keywords

• biomechanics
• hip fracture
• hip protector
• fall
• impact simulations
• impact experiments