Types of wheelchairs.

*Dimensions given here for seat width and depth relate to space available to the occupant and are not overall dimensions for the chair or its components . floor vary with the width approximately as shown in Table 1. Selection of the proper seat width is important to comfort and stability . A seat too narrow is not only uncomfortable, but access to the chair is made difficult. Furthermore, the chances of pressure sores developing is increased. A seat that is too wide encourages the user to lean toward one side, thus promoting scoliosis and increased pressure over the buttocks on one side . In addition, a seat wider than is necessary makes propulsion more difficult. A seat that is too shallow reduces the area in contact with the seat and causes more pressure on the soft tissues in contact with the seat than is necessary . Furthermore, the footrests do not support the feet and legs properly, and balance of the user is affected. A seat that is too deep, or longer than it should be, can restrict circulation in the legs, and causes the patient either to sit with his legs extended or to slide forward in the chair.