The effects of body mass composition and cushion type on seat-interface pressure in spinal cord injured patients

Abstract

Objective: To investigate the effects of body mass composition and cushion type on seat-interface pressure in spinal cord injured (SCI) patients and healthy subjects. Methods: Twenty SCI patients and control subjects were included and their body mass compositionmeasured. Seat-interface pressure was measured with participants in an upright sitting postureon a wheelchair with three kinds of seat cushion and without a seat cushion. We also measured the pressure with each participant in three kinds of sitting postures on each air-filled cushion. We used repeated measure ANOVA, the Mann-Whitney test, and Spearman correlation coefficient for statistical analysis. Results: The total skeletal muscle mass and body water in the lower extremities were significantly higher in the control group, whilst body fat was significantly higher in the SCI group. However, the seat-interface pressure and body mass composition were not significantly correlatedin both groups. Each of the three types of seat cushion resulted in significant reduction in the seat-interface pressure. The SCI group had significantly higher seatinterface pressure thanthe control group regardless of cushion type or sitting posture. The three kinds of sitting posture did not result in a significant reduction of seat-interface pressure. Conclusion: We confirmed that the body mass composition does not have a direct effect on seat-interface pressure. However, a reduction of skeletal muscle mass and body water can influence the occurrence of pressureulcers. Furthermore, in order to minimize seat-interface pressure, itis necessary to apply a method fitted to each individual rather than a uniform method.