Sitting with adjustable ischial and back supports: biomechanical changes.
Sitting with adjustable ischial and back supports: biomechanical changes.
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坐骨和背部支撑可调节：生物力学变化。
DOI：
10.1097/01.brs.0000068243.63203.a8
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发表时间：
2003
期刊：
影响因子：
3
通讯作者：
Zhang,Li-Qun
中科院分区：
文献类型：
--
作者：
Makhsous,Mohsen;Lin,Fang;Hendrix,RonaldW;Hepler,Matthew;Zhang,Li-Qun
研究设计。通过运动学、动力学、肌电图和放射学测量，研究了坐骨和坐骨靠背可调节的新坐位设计对坐骨和靠背的接触力、压力分布、腰椎前凸和腰背部肌肉活动的影响。背景资料摘要。坐着可能导致骨盆后旋，腰椎前凸减轻，肌肉紧张、椎间盘压力、坐骨和尾骨压力增加，这些可能与腰痛有关。一种减轻坐骨负荷和保持腰椎前凸的装置可能有助于增加坐位舒适度和减轻腰痛。方法：对15名没有腰痛病史的办公室职员进行了测试。测量了有坐骨支撑和无坐骨支撑及可调节坐骨支撑时，坐骨与大腿、臀部与座椅、背部与靠背之间的接触压力分布、反作用力、坐垫与靠背所承受的载荷、骶骨倾斜度、腰椎前凸度、腰椎椎间隙、稳定躯干的肌肉活动。座椅压力中心峰值向大腿方向显著前移（P< 0.002）。坐垫和靠背的总接触面积分别显著减小和增大（P< 0.001）。结论：坐骨支撑减少、坐骨靠背固定于下脊柱时，坐骨支撑减少，坐骨下压力峰值降低，肌肉活动减少，坐骨前凸和腰椎前凸保持不变，骶骨前旋，腰椎前凸与坐骨前凸、腰椎前凸、腰椎椎间盘高度均显著增加。增加腰椎间盘高度，这可能会减轻腰痛。
Study Design.The seat and back contact force, pressure distribution, lumbar lordosis, and low back muscle activities associated with a new seat design with adjustable ischial support and backrest were investigated using kinematic, kinetic, electromyographic, and radiographic measurements.Objectives.To investigate the biomechanical effects of adjusting ischial and backrest supports during sitting.Summary of the Background Data.Sitting may induce posterior rotation of the pelvis, reduction of lumbar lordosis, and increases in muscle tension, disc pressure, and pressure on the ischium and coccyx, which may be associated with low back pain. A device that reduces the ischial load and maintains lumbar lordosis may help increase seating comfort and reduce low back pain.Methods.Fifteen office workers with no known low back pain history were tested. Contact pressure distributions, reaction forces between the buttock-thighs and seat and between the back and backrest, load carried by the seat pan and backrest, sacral inclination, lumbar lordosis, intervertebral space of lumbar spine, and muscular activity in stabilizing the trunk were measured for sitting with and without ischial support and with adjustable back support.Results.When the ischial support was relieved, the center of the force on the seat and on the legs of the chair, and the peak center of pressure on the seat, were significantly (P< 0.002) shifted forward toward the thighs. The total contact area on the seat pan and on the backrest was significantly decreased and increased, respectively (P< 0.001). The sacral inclination, total and segmental lumbar lordosis, and lumbar spine disc height were significantly increased for sitting upright with backrest, with the lumbar curve close to that during standing.Conclusions.Sitting with reduced ischial support and fitted backrest to the lower spine altered the contact area, reduced peak pressure under the ischia, reduced muscular activity, maintained total and segmental lumbar lordosis, rotated the sacrum forward, and increased lumbar intervertebral disc heights, which could potentially reduce low back pain.