The Effect of Chair Designs on Sitting Pressure Distribution and Tissue Perfusion

Objective: The aim of this study was to investigate the effect of five chair designs on interface pressure distribution and tissue perfusion in the buttock-thigh region. Background: Prolonged sitting has been found to contribute to the symptoms of work-related low back pain. Studies have found that chair design affects users' sitting posture and comfort. As sitting applies pressure to the user, it is necessary to investigate how chair design affects sitting pressure and tissue perfusion during sitting. Method: We tested five chair designs (Suspension A, Suspension B, Foam A, Foam B, and bicompliant) on 15 young, healthy females. Sitting interface pressure and buttock-thigh tissue perfusion (in terms of transcutaneous partial pressure of oxygen and carbon dioxide, tcPO(2) and tcPCO(2), respectively) were measured during 10-min sitting on each chair. Results: We found that chair design significantly affected the distribution of the sitting pressure (p < .001) and buttock-thigh tissue perfusion (p < .023). Average pressure and total contact area were found highest in both foam designs, and the average pressure was the lowest in one of the suspension designs. Across all tested chair designs, the anterior portion of the seat sustained the lowest contact pressure. It was also found that tcPO(2) was the lowest (p < .003) and tcPCO(2) was the highest (p <.001) in tissue around ischial tuberosity for all chair designs. Conclusion: Chair design and materials of the seat significantly affect the sitting interface pressure distribution and tissue perfusion in sitting area. Further evaluation of these outcomes may provide useful information to correlate chair design with sitting comfort.