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

Understanding the nature of blunt force trauma and the energies involved is key to their effective attenuation. This study compares and analyses the energy absorbance of various combinations of hip protectors and flooring materials to identify fracture prevention design variables. Improved understanding and prevention is critical with an estimated 4.5 million people worldwide suffering a hip fracture each year by 2050. Testing is performed using a dynamic impact rig instrumented with linear encoders and a piezoelectric impact load cell. This allows for high rate force and displacement measurement to be achieved during impact. Results show the effects of deceleration rate on peak load and measurably define the impact pattern for a range of protective materials with compliant flooring and hip protectors reducing impact forces below the suggested fracture threshold (3742N). Flooring type is shown to significantly affect the performance of protective pads. A combination of soft shell protector with carpet and underlay showed the highest force attenuation (68%). The study shows 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 will also inform the future development of gradient-density protective aids.