Center for Physical Ergonomics, Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA 01748, USA.
Hum Factors. 2013 Apr;55(2):309-22. doi: 10.1177/0018720812454539.
The purpose of the study was to quantify maximum acceptable torques (MATs) in 16 healthy male industrial workers while performing six motions: screw driving clockwise with a 40 mm handle and a 39 mm yoke handle, flexion and extension with a pinch grip,ulnar deviation with a power grip (similar to knife cutting), and a handgrip task (similar to a pliers task).
Psychophysical studies on repetitive motions of the wrist and hand were previously reported on women; however, it is not clear how men will psychophysically respond to similar motions.
A psychophysical methodology was used in which the participant adjusted the resistance on the handle. Repetition rates for these tasks were 15 and 25 per minute. Participants performed the tasks for 7 hours per day, 5 days per week, and for 12 days. Symptoms were recorded by the subjects at the end of each hour.
The mean MATs ranged from 1.15 Nm to 1.88 Nm for screw driving, 2.26 Nm to 3.71 Nm for pinch flexion and extension, 3.88 Nm to 4.07 Nm for ulnar deviation, and 11.47 Nm to 13.98 Nm for the handgrip task. The higher the repetition rate, the lower the MAT. Depending on the type of task and repetition rate, these values represented 15% to 35% (median of 23%) of their maximum isometric torque.
Based on aforementioned findings, a table of MATs and derived acceptable forces for six tasks at different percentage capabilities of the male industrial populations is formulated.
本研究旨在量化 16 名健康男性工业工人在进行 6 种运动时的最大可接受扭矩（MAT）：顺时针用 40 毫米手柄和 39 毫米轭手柄拧螺丝、用捏夹握持弯曲和伸展、用动力握持（类似于切刀）进行尺侧偏斜以及手握任务（类似于钳子任务）。
先前有研究报告了手腕和手部重复性运动的心理物理学研究，但尚不清楚男性在心理物理学上会如何对类似运动做出反应。
采用心理物理学方法，参与者调整手柄上的阻力。这些任务的重复率为每分钟 15 次和 25 次。参与者每天工作 7 小时，每周工作 5 天，共 12 天。在每小时结束时，受试者记录症状。
拧螺丝的平均 MAT 范围为 1.15 Nm 至 1.88 Nm，捏夹弯曲和伸展的 MAT 范围为 2.26 Nm 至 3.71 Nm，尺侧偏斜的 MAT 范围为 3.88 Nm 至 4.07 Nm，手握任务的 MAT 范围为 11.47 Nm 至 13.98 Nm。重复率越高，MAT 越低。根据任务类型和重复率的不同，这些值代表其最大等长扭矩的 15%至 35%（中位数为 23%）。
基于上述发现，制定了一个表格，列出了不同男性工业人群能力百分比下六种任务的 MAT 和衍生的可接受力。
