Rantanen P, Airaksinen O, Penttinen E
Paavo Nurmi Center, Sports Medical Research Unit, University of Turku, Finland.
Eur J Appl Physiol Occup Physiol. 1994;68(4):322-6. doi: 10.1007/BF00571451.
The aim of this study was to illustrate the influence of different levels of the fulcrum (the axis of sagittal rotation) on measured trunk flexion and extension strength and compare force and torque as a unit of measure. The isometric trunk strength was measured in 16 healthy female subjects. The dynamometer was kept at the shoulder level and the moment arm was lengthened step by step by moving the fulcrum caudally from the level of the posterior superior iliac spine to the level of the gluteal fold. The moment of force (torque) increased from 117.0 to 208.5 N.m in flexion and from 182.2 to 292.5 N.m in extension, P < 0.0001. An attempt to quantify this change was made. Paradoxically, the measured force remained at a constant level (in flexion) or slightly decreased (in extension). We concluded that torque as a measure of trunk flexion and extension strength is highly dependent on the level of the rotation axis and force appears to be less sensitive for variations with the height of the fulcrum. We would suggest that the observed increase in torque is physiological and reflects to what extent hip flexor or extensor muscles are recruited. The force, on the other hand, may better characterize a person's capability to perform functional tasks. Force and torque should strictly be distinguished from one another.
本研究的目的是阐明不同水平的支点（矢状面旋转轴）对所测量的躯干屈伸力量的影响，并比较作为测量单位的力和扭矩。对16名健康女性受试者测量了等长躯干力量。测力计保持在肩部水平，通过将支点从后上棘水平向尾侧移动至臀褶水平，使力臂逐步延长。在屈曲时，力矩（扭矩）从117.0 N·m增加至208.5 N·m，在伸展时从182.2 N·m增加至292.5 N·m，P<0.0001。尝试对这一变化进行量化。矛盾的是，所测量的力在屈曲时保持在恒定水平，在伸展时略有下降。我们得出结论，作为躯干屈伸力量测量指标的扭矩高度依赖于旋转轴水平，而力对于支点高度变化似乎不太敏感。我们认为所观察到的扭矩增加是生理性的，反映了髋部屈肌或伸肌被募集的程度。另一方面，力可能更能表征一个人执行功能性任务的能力。力和扭矩应严格区分开来。
