The mechanical properties of the human subcalcaneal fat pad in compression.

The subcalcaneal fat pads of Homo sapiens were subjected to cyclic compressive loading in a materials testing machine. Rates of loading and the absolute loads to which pads were subjected were chosen to simulate the pattern of forces that the pad would be exposed to during the ground contact phase of the running step. Heel pads were found to be resilient, returning approximately 70% of the energy used to deform them. This was modified little by changes in loading frequency. A reduction of temperature from 37 degrees C to 10 degrees C produced a small, but significant, increase in the percentage energy dissipation.