The function of the rump in relation to sitting and the Keane Reciprocating Wheelchair Seat

Abstract

There is no appliance which will prevent decubiti in the immobile patient. Rump function in relation to man is discussed. Body weight is carried on the skeleton and transmitted to a natural surface, i.e. the ground via weight bearing superficial bony prominences. These protect vital structures: muscle, urethra, nerves, arteries from the effects of pressure. Convential seat appliances are unscientific, and seek to relieve pressure on the skin in the area of the ischia by transferring pressure to the soft tissues. Consequently, the physiological condition is reversed, the skeleton and body weight is supported on vital tissues. This leads to serious and deep necrosis which starts within the warm ischaemic muscle survival time which is much shorter than survival time for skin.It would appear that there is no safe method of preventing decubiti except the normal physiological means: mobilisation of the patient.The Keane Reciprocating Wheelchair Seat consists substantially of an outer support means of conventional toilet seat shape and an inner mechanically operated central seat which lifts the patient in a physiological way on the ischia once every 9 min, thus there is adequate transfer of weight from one large area of the buttocks to another. Therefore prolonged ischaemia is avoided. It has been observed that under restoration of adequate mobility ischial decubiti will heal. Intermittent pressure produced by body weight is normal for tissue and repair by cicatrisation. Consequently, bedrest with interruption of occupation is not necessary in the treatment of ischial sores.