The force attenuation effect of foam mattress in simulated sideways fall of hip on level surface

Abstract

While there have been studies on the: impact attenuation of different floor coverings, the effectiveness of using foam mattress as protective floor covering against geriatric hip fracture is still unknown. The objective of current study is to compare the force attenuation of foam mattress with that of teak wooden block when subjected to an impact force that the human hipbone would experience in accidental fall. A porcine hip fall simulator which consisted of a 12-kg impactor and a surrogate pelvis made by 8 month old porcine hipbone and with effective stiffness of 75 kN/m was set up to simulate sideways fall of human hip. The porcine hip fall simulator was allowed to drop freely on the surrogate pelvis from a height starting from 10 cm to a final height of 50 cm. The results showed the use of one piece and two pieces of foam mattress provided significant force reduction ranging from 21% to 37% and from 38% to 61% respectively when compared to wooden impact, and the optimal force reduction occurred when impact energy approached 18 to 24 joules. We found the foam mattress worked best only in those falls where the impact load was of relatively low energy. Relevance: Prevention of geriatric hip fractvre is one of the major health issues in the foreseeable future. This study highlight the fact that the use of a protective floor covering may reduce the impact force on the hip in accidental fall and could be a relatively economical and practical way to reduce the risk of geriatric hip fracture.