Modelling Human-Structure Interaction in Sideways Fall for Hip Impact Force Estimation

Sideways fall-induced hip fracture is a primary global health concern among the elderly. Existing impact models for predicting peak hip impact force mostly consider the human body-related parameters rather than impact surface parameters. This study proposed improving existing spring-mass-damper models by accounting for the human-structure dynamic interaction during sideways fall for better predicting peak impact force on the hip. Information required to construct the models was extracted from the literature. Different peak hip impact forces were estimated by considering differences in gender, body height, body mass, stiffness, damping coefficients of body tissue over the greater trochanter, and the impact surface stiffness. The predicted peak hip impact forces were compared to measured or simulated results in the literature and found to agree reasonably. Simulation results show that interactions with impact surfaces with lower stiffness can reduce the value of peak impact force applied on the hip by at least 16%