Comparison of impact energy absorbance by various combinations of hip protector and flooring material

Abstract

Background: Understanding the nature of blunt force trauma and the energies involved is key to their effective attenuation. This study compares and analyzes the energy absorbance of various combinations of hip protectors and flooring materials to identify fracture prevention design variables. Methods: Testing was performed using a dynamic impact rig instrumented with linear encoders and a piezoelectric impact load cell, which allows for high rate of force and displacement measurements to be achieved during impact. Results show the effects of deceleration rate on peak load and measurably define the impact patterns for a range of protective materials, with compliant flooring and hip protectors reducing impact forces below the suggested fracture threshold (3742N). Results: The force reduction provided by a hip protector depends on the type of flooring and is greatest for falls onto carpet with a foam underlay. A combination of soft-shell protector with carpet and underlay showed the highest force attenuation (68%). Conclusions: The study showed that the effective selection and implementation of hip protectors in homes and care facilities must include the consideration of flooring type. The identification of peak deceleration rates also will inform the future development of multi-material protective aids.