ABSTRACT

Objectives. Tendonitis and carpal tunnel syndrome are common cumulative trauma disorders that can occur with repetitive usage of pistol grip power tools. The role of reaction torque resulting in a forceful rotary displacement of the tool handle, as well as the role of applied grip force, is not clear in the development of these disorders. This study aimed to quantify the flexor tendon strains and median nerve pressure during a typical power tool operation securing a threaded fastener. Methods. Six fresh-frozen cadaver arms were made to grip a replica pistol grip power tool using static weights to apply muscle forces. A 5-Nm torque was applied to the replica power tool. The median nerve pressure and strains in the flexor digitorum profundus and superficialis tendons were measured using a catheter and strain gauges, at three wrist flexion angles. Results. The peak tendon strains were between 1.5 and 2% and were predominantly due to the grip force more than the transmitted torque. Median nerve pressure significantly increased with the wrist flexed versus extended. Conclusion. The results indicate that the contribution of the grip force to the tendon strain and median nerve pressure was greater than the contribution from the reaction torque.

摘要

目标。肌腱炎和腕管综合征是常见的累积性创伤疾病，可能因重复使用手枪式电动工具而发生。在这些疾病的发展过程中，反作用扭矩的作用导致工具手柄的有力旋转位移，以及所施加的握力的作用尚不清楚。本研究旨在量化固定螺纹紧固件的典型电动工具操作过程中的屈肌腱拉伤和正中神经压力。方法。制作了六个新鲜冷冻的尸体手臂来握住复制的手枪式握把电动工具，使用静态重量来施加肌肉力。将 5-Nm 扭矩施加到复制电动工具上。使用导管和应变仪在三个腕屈曲角度测量指深屈肌和浅表肌腱的正中神经压力和应变。结果。肌腱应变峰值在 1.5% 和 2% 之间，主要是由于握力大于传递的扭矩。腕部弯曲与伸展时，正中神经压力显着增加。结论。结果表明，握力对肌腱应变和正中神经压力的贡献大于反作用力矩的贡献。