McFadyen G M, Stoner D L
Arch Phys Med Rehabil. 1980 May;61(5):234-7.
The supportive properties of polyurethane foam wheelchair cushions change significantly during the first hours of use. Thus, cushions which initially appear to optimally distribute the patient's weight may not do so after a break-in period. To solve this problem, a cushion prestressing protocol has been devised which breaks-in the foam cushion prior to determination of the patient's pressure distribution. It was found that the useful life of these cushions is adversely affected by heavy static loading and high temperatures, and if allowed to rest, polyurethane foam cushions recover a portion of their original load-bearing properties.
聚氨酯泡沫轮椅坐垫的支撑性能在使用的最初几个小时内会发生显著变化。因此，最初看似能最佳分配患者体重的坐垫，在磨合期后可能无法做到这一点。为了解决这个问题，已设计出一种坐垫预加应力方案，在确定患者压力分布之前对泡沫坐垫进行磨合。结果发现，这些坐垫的使用寿命会受到重静态负荷和高温的不利影响，并且如果让聚氨酯泡沫坐垫静置，它们会恢复部分原始承重性能。
