Evaluation of methods for determining rearward static stability of manual wheelchairs.

Wheelchair standards have been under development for several years. A set of tests has been approved by the American National Standards Institute (ANSI) and by the International Standards Organization (ISO) but continue to be refined. Static stability is one of the indicators used to evaluate manual wheelchairs and is measured by placing a loaded wheelchair on a platform that is tilted until the wheelchair's front wheels lift off of the platform. Currently, if the wheelchair parking brakes slip, a block is placed behind the rear wheels and the tip angle is measured. The results for eight different wheelchairs with three load cases showed that the rearward tip angle for the block is significantly different (p < 0.05) from that with the brakes alone.