Effect of Wheelchair Design on Posture and Comfort of Users

Abstract

The canvas sling seat and backrest incorporated into a conventional wheelchair provide a seating system which fails short of many basic ergonomic requirements, which may compromise the comfort, health and level of dependency of the user. The high incidence of back pain among able-bodied people gives rise to much concern. Yet although there are indications that a similar proportion suffer, back pain in the disabled population receives less specific attention. Two prospective studies were undertaken involving a total of 58 subjects. The first evaluated the effects of wheelchair design on posture and the second looked at the effects that this had on the comfort of the user. Posture was recorded using a technique for measuring spinal curves, and data on the comfort of each seat were collected by questionnaire. The studies evaluated three different seating systems. The first was that of a conventional model 8BL wheelchair; the second and third were experimental rigs incorporated into an 8BL frame. One rig had cushions chamfered to fit the concavities of the canvas seat and backrest and the second had a rigid base on which was mounted cushioning material. The unmodified 8BL was shown to encourage a kyphotic posture and caused discomfort in both able-bodied and disabled subjects especially in the neck and back. The two experimental rigs promoted an acceptable degree of lordosis and, although both proved more comfortable than the canvas seat, of the two the hard-based seat was preferred. The canvas sling seat and backrest incorporated into a conventional wheelchair provide a seating system which fails short of many basic ergonomic requirements, which may compromise the comfort, health and level of dependency of the user. The high incidence of back pain among able-bodied people gives rise to much concern. Yet although there are indications that a similar proportion suffer, back pain in the disabled population receives less specific attention. Two prospective studies were undertaken involving a total of 58 subjects. The first evaluated the effects of wheelchair design on posture and the second looked at the effects that this had on the comfort of the user. Posture was recorded using a technique for measuring spinal curves, and data on the comfort of each seat were collected by questionnaire. The studies evaluated three different seating systems. The first was that of a conventional model 8BL wheelchair; the second and third were experimental rigs incorporated into an 8BL frame. One rig had cushions chamfered to fit the concavities of the canvas seat and backrest and the second had a rigid base on which was mounted cushioning material. The unmodified 8BL was shown to encourage a kyphotic posture and caused discomfort in both able-bodied and disabled subjects especially in the neck and back. The two experimental rigs promoted an acceptable degree of lordosis and, although both proved more comfortable than the canvas seat, of the two the hard-based seat was preferred. Biography: Michele Harms qualified as a physiotherapist in 1982 and worked for four years at The Royal Free Hospital. During this time she spent six months in Cape Town at Groote Schuur Hospital on a working exchange. This study was initiated as a result of her interest in improving posutre and lessening the back pain felt by wheelchair users. Since completing this project she has been working as a superintendent research physiotherapist in the Bloomsbury Health District.