Arborelius U P, Wretenberg P, Lindberg F
Department of Anatomy, Karolinska Institute, Stockholm, Sweden.
Ergonomics. 1992 Nov;35(11):1377-91. doi: 10.1080/00140139208967399.
The loading moment of force on the hip, knee, and ankle joints of nine healthy men rising from four different types of stools were compared, together with the levels of myoelectrical activity (EMG) in four leg muscles. Two types of stool (stand stools) had higher seats than a normal chair. The other two were of ordinary seat height, but one also had armrests. The bodyweight carried by the different stools when sitting was also measured, and the subject estimated the effort required for each trial. The mean maximum knee moment was over 60% lower when rising from the high stool than from 'ordinary' seat height. The difference between the high and low stand stool was also significant (p less than 0.001). Using the high stool or help of the arms reduced the mean maximum hip moment by about 50%. The mean maximum ankle moment was only marginally influenced by the different stools. Knee moment was influenced more by seat height than was hip moment. Vastus lateralis activity was significantly higher when subjects rose from 'ordinary' height than when rising from either stand stool (p less than 0.001). The rectus femoris muscle was little activated and the semitendinosus muscle was activated earlier when rising from higher seat heights. All subjects estimated the effort of rising from the higher stand stool to be lower than from the lower stand stool or from 'ordinary' height without arm rests. It was concluded that stand stools are good alternatives for workers who change frequently between sitting and standing work.
比较了九名健康男性从四种不同类型的凳子上起身时髋关节、膝关节和踝关节的加载力矩，以及四块腿部肌肉的肌电活动（EMG）水平。两种凳子（站立凳）的座位比普通椅子高。另外两种凳子的座位高度正常，但其中一种还有扶手。还测量了不同凳子上坐姿时所承受的体重，并且让受试者估计每次试验所需的力气。从高凳子上起身时，平均最大膝关节力矩比从“普通”座位高度起身时低60%以上。高站立凳和低站立凳之间的差异也很显著（p小于0.001）。使用高凳子或借助扶手可使平均最大髋关节力矩降低约50%。不同凳子对平均最大踝关节力矩的影响很小。膝关节力矩受座位高度的影响比髋关节力矩更大。当受试者从“普通”高度起身时，股外侧肌的活动明显高于从任何一种站立凳起身时（p小于0.001）。从较高座位高度起身时，股直肌几乎不被激活，半腱肌更早被激活。所有受试者都估计从较高的站立凳起身比从较低的站立凳或没有扶手的“普通”高度起身更省力。得出的结论是，站立凳是经常在坐姿和站姿工作之间转换的工人的良好选择。
