Biomechanical evaluation of four different mattresses.

This study provided an objective, biomechanical comparison of four "top of the line" mattresses from four different manufacturers using two different measurements. One, which has been used in other studies, was pressure distribution patterns-evaluating maximum pressures generated by an individual lying supine on the mattresses. The other was a novel approach developed specifically for this study-quantifying the degree of spinal distortion induced when in the side posture position. Eighteen normal adult males of similar height but in three different weight groups were tested using both of these approaches on each of four mattresses. As expected, greater maximum pressure directly related to subject's weight group and was greater in the pelvic compared to the thoracic region. One mattress did induce significantly lower maximum pressures than the other three in both the pelvic and thoracic regions. Spinal distortion was not reliably different across the four mattresses in five of the seven spine regions evaluated. However, at the T1/T3 and the T6/T8 spinal segments, inconsistent but statistically significant separation between some mattresses was observed.