Development of an Experimental Hip Impact Model to Test Hip Protectors

INTRODUCTION HIP FRACTURES, which represent a severe health problem for the elderly, typically result in sideways falls with a direct impact to the hip (Kannus et al. 1999). One possibility to prevent hip fractures is the use of hip protectors. At present, mainly two types of products, namely energy-absorbing soft pads and energy-shunting hard shells are used to protect the hip from impact loads in the area of the trochanter major. Mechanical testing is an important tool to assess the efficacy of hip protectors, and to support the development and optimisation of protector materials and designs. In testing systems used so far (Parkkari et al. 1995; Robinovitch et al. 1995; Mills 1996; Nabhani and Bamford 2002) the mechanical and geometrical properties of the human hip were strongly simplified, so that neither practical wearing conditions of hip protectors nor their deformation and distribution of impact forces could be simulated realistically.