A support contour of a cushion, such as a wheelchair cushion, defines relief areas at locations adjacent to skin covering the ischial tuberosities, the greater trochanters and the coccyx and sacrum of a person sitting on the support contour. Support areas of the support contour transfer force into the...http://www.google.com.au/patents/US7216388?utm_source=gb-gplus-sharePatent US7216388 - Contoured seat cushion and method for offloading pressure from skeletal bone prominences and encouraging proper postural alignment
