The 'hammock' effect in wheelchair cushion covers

It is necessary to cover wheelchair cushions in order to protect the load distributing elements from wear and contamination. It is widely supposed that the more rigid covers may impair the load distributing properties of the cushion by the so-called 'hammock' effect. Measurements have therefore been taken of cushion deformation and seating pressures using a standard Department of Health wheelchair cushion with a variety of covers to determine the degree of impairment. The results indicate that the cushion cover 'hammock' effect may be ignored for practical purposes.