Effect of different seat heights on lumbar spine flexion during stand-to-sit motion.

[Purpose] This study aimed to investigate the movement of the thorax, lumbar spine, and pelvis when healthy participants sit on a chair, and to identify the kinematic characteristics due to changes in the height of the seat. [Participants and Methods] Twenty healthy participants (14 males, 6 females; mean age, 29 ± 5 years) were recruited for this study. They performed stand-to-sit motion using one seat with a height of 100% that of the lower leg length (standard) and another with a height of 60% that of the lower leg length (lower).