Measuring tissue perfusion during pressure relief maneuvers: insights into preventing pressure ulcers.

Background/objective: To study the effect on tissue perfusion of relieving interface pressure using standard wheelchair pushups compared with a mechanical automated dynamic pressure relief system.

Design: Repeated measures in 2 protocols on 3 groups of subjects.

Participants: Twenty individuals with motor-complete paraplegia below T4, 20 with motor-complete tetraplegia, and 20 able-bodied subjects.