Sitting pressure-time patterns in patients with quadriplegia.

Continuous pressure under each ischial tuberosity was measured on five ulcer-free patients with quadriplegia for four days as they completed their normal daily activities. Results showed many multihour periods without pressure relief. More than 50% of the time the pressure-time periods were outside of previously reported acceptable limits. The results indicate that quadriplegic patients can sit with ischial tuberosity pressures above the previously reported capillary pressure of 32mmHg for long periods of time without getting an ulcer. This study suggests that other factors beside pressure must be studied in order to develop a better resting surface.