Effect of soft shell hip protectors on pressure distribution to the hip during sideways falls

Abstract

While hip protectors represent a promising strategy for preventing hip fractures, clinical efficacy has been limited by poor user compliance. Soft shell protectors may be more acceptable to users than traditional hard shell designs. However, before embarking on clinical trials to assess efficacy, laboratory experiments are required to determine how soft shell protectors affect the force applied during impact to the hip. This was the goal of the current study. Fifteen women participated in "pelvis release experiments," which safely simulate the impact stage of a sideways fall. During the trials, we measured total impact force and mean pressure over the greater trochanter with the participant unpadded, and while wearing two commercially available soft shell protectors. Mean pressure over the greater trochanter was reduced by 76% by a 14-mm thick horseshoe-shaped protector and by 73% by a 16-mm thick continuous protector. Total force was reduced by 9% by the horseshoe and by 19% by the continuous protector. Soft shell hip protectors substantially reduce the pressure over the greater trochanter, while only modestly reducing total impact force during simulated sideways falls. These data support the need for clinical trials to determine whether soft shell protectors reduce hip fracture risk in vulnerable populations.