Effect of seat thickness on peak femoral vein velocity

Abstract

IntroductionThis study aimed to investigate the effects of different seat thicknesses on lower limb momentum and lower limb blood flow in a narrow enclosed space simulating public places. MethodsWe enrolled 15 female volunteers. We measured the maximum venous blood flow velocity (peak velocity [PV]) of the superficial femoral vein, the range of knee joint movements, and the number of knee joint movements while the subjects sat on the thicker- or thinner-tip seat for 140 min. ResultsThere was a difference in the change rate of PV after 140 min of sitting: thinner-tip seat groups: 22.3% (−31.1 − −13.5%); thinner-tip seat groups: 6.9% (−16.5 − 2.8%) (P < 0.001). There was a significant difference in the range of knee joint motion between the two seats: thicker-tip seat: 24.5° (19.9°–29.1°); thinner-tip seat: 36.6° (29.1°–44.1°) (P = 0.01). There was a significant positive correlation between the change rates of PV and the knee joint range of motion (r = 0.41, P = 0.03). ConclusionsOur findings suggest that a seat structure that does not restrict lower limb movement may help inhibit reductions in lower limb blood flow when sitting for long periods.