Measurement of support surface efficacy: pressure.

Two methods can be used to assess the relative pressure-relieving/pressure-reducing effects of clinical support surfaces. The interaction occurring at the interface between the human body and the support surface--known as the interface pressure--can be measured with an interface pressure system. Reactive hyperemia, the physiologic response to pressure, can be measured with thermography and laser Doppler flowmetry. Using mannequins and human subjects that represent typical body types in the older population, a protocol was developed for collecting data on the effects of support surfaces on interface pressure and reactive hyperemia.