The biomechanics of hip protectors.

The mode of action of one design of hip protector was investigated. A dummy femur surrounded by a flesh substitute was impacted from a range of heights while the forces on the trochanter and the surrounding flesh were measured. The protector doubled the estimated fall distance for fracture of the trochanter. The protection mechanisms are load transfer to the muscles of the thigh and energy absorption in the protector. Hip protectors could absorb more energy safely if they were thicker, or if the shell design was modified.