Retention of supportive properties by eggcrate and foam wheelchair cushions

This study investigated the reported lack of ability of the eggcrate cushion (EC) to provide wheelchair users with adequate support necessary for comfort and tolerably low-peak sitting pressures over time. The primary parameter used to quantify the ability of the cushion to distribute load was the indention force deflection (IFD) metric. The EC was compared to a high-density planar foam cushion (HD). The IFD was measured for both cushions after successive periods of compression to simulate use. Study results failed to support the common perception that the soft EC would lose its supportive properties more rapidly than the much firmer HD cushion. Although the initial IFD of the EC was much lower than that of the HD, a smaller percentage of its IFD was lost after compression. This difference between the two cushions likely was due to differences in packaging. The EC was rolled into a cylinder, compressing it to 60% of its original thickness; the HD was packaged without compression.