Effect of a Dynamic Air Cushion on the Development of Leg Edema during Wheelchair Sitting

[Purpose] To clarify how a novel dynamic cushion affects the leg edema evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with the dynamic air cushion or a static cushion. [Subjects and Methods] Nine healthy male subjects participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed around the middle portion of the lower thigh). Following a period of rest, each subject was asked to sit on a wheelchair containing the dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The angles of the knee and ankle joints were set to 90 degrees, and no footrests were used. [Results] The change in leg volume observed during sitting on the dynamic cushion (0.00 ± 0.03 mL/100 mL) was smaller than that observed during sitting on the static cushion (0.02 ± 0.02 mL/100 mL). [Conclusion] These results suggested that the dynamic cushion relieved leg edema during wheelchair sitting.