Ohkawa Takahiro, Atomi Tomoaki, Hasegawa Katsuya, Atomi Yoriko
Department of Physical Therapy, Faculty of Health Science Technology, Bunkyo Gakuin University, 1196 Kamekubo, Fujimino-shi, Saitama 356-8533, Japan; Department of Material Health Science, Faculty and Graduate School of Engineering, Tokyo University of Agriculture and Technology, 204 Research Center for Science and Technology, Koganei-shi, Tokyo 184-8588, Japan.
Department of Physical Therapy, Faculty of Medical Sciences, Teikyo University of Science, 2525 Yatsuzawa, Uenohara-shi, Yamanashi 409-0193, Japan.
Gait Posture. 2017 Oct;58:415-420. doi: 10.1016/j.gaitpost.2017.09.002. Epub 2017 Sep 5.
During walking, the friction between the foot and the ground surface causes a free moment (FM), which influences the torsional stress on the lower extremity. However, few studies have investigated the FM during natural walking. The main aim of this study was to examine the relationship between the FM and the absolute and relative rotation angles of the foot and pelvis.
The rotation angles of foot and pelvic were measured in 18 healthy men using a motion capture system. Rotation angles were measured in absolute and relative coordinates as well as in reference to the line connecting the center of pressure (CoP) line under the right and left feet to evaluate the effects of the opposite lower limb on the FM. The absolute and relative rotation angles of the foot and pelvis were entered into forced-entry linear regression models to evaluate the influence on the FM.
Only the relative angle of rotation between the foot and pelvis could explain the prediction equations significantly. In the Pearson's product-moment correlation coefficient, the rotation angles of the foot and pelvis defined using the bilateral CoP points had not significantly correlated with FM. No joint rotation movement was correlated with FM.
The torsion of the entire lower extremity should be performed principally through hip internal rotation. When evaluating the FM as a torsional stress, focusing on the rotation of the entire lower extremity, rather than on one segment, is beneficial.
在行走过程中，脚与地面之间的摩擦力会产生一个自由力矩（FM），该力矩会影响下肢的扭转应力。然而，很少有研究调查自然行走过程中的自由力矩。本研究的主要目的是检验自由力矩与脚和骨盆的绝对及相对旋转角度之间的关系。
使用运动捕捉系统测量了18名健康男性的脚和骨盆的旋转角度。以绝对坐标和相对坐标以及参照连接左右脚下方压力中心（CoP）线的直线来测量旋转角度，以评估对侧下肢对自由力矩的影响。将脚和骨盆的绝对及相对旋转角度输入强制进入线性回归模型，以评估对自由力矩的影响。
只有脚和骨盆之间的相对旋转角度能够显著解释预测方程。在皮尔逊积差相关系数中，使用双侧CoP点定义的脚和骨盆的旋转角度与自由力矩没有显著相关性。没有关节旋转运动与自由力矩相关。
整个下肢的扭转主要应通过髋关节内旋来进行。在将自由力矩作为扭转应力进行评估时，关注整个下肢的旋转而非单个节段是有益的。
