Turcotte Kaylyn E, Kociolek Aaron M
School of Physical and Health Education, Nipissing University, North Bay, Ontario, Canada.
PeerJ. 2021 Mar 19;9:e11038. doi: 10.7717/peerj.11038. eCollection 2021.
We assessed median nerve travel and deformation concurrently to better understand the influence of occupational risk factors on carpal tunnel dynamics, including forceful chuck gripping and deviated wrist positions.
Fourteen healthy right-hand dominant participants performed a chuck grip in 6 experimental conditions: two relative force levels (10% and 40% of maximum voluntary effort); three wrist positions (15° radial deviation, 0° neutral, 30° ulnar deviation). Chuck grip forces were measured with a load cell while the transverse cross-section of the carpal tunnel was imaged via ultrasound at the distal wrist crease. Images of the median nerve were analyzed in ImageJ to assess cross-sectional area, circularity, width, and height as well as travel in the anterior-posterior and medial-lateral axes.
We found a main effect of deviated wrist position on both anterior-posterior and medial-lateral travel, with the greatest nerve travel occurring in 30° ulnar deviation. There was also a significant interaction between chuck grip force and deviated wrist position on cross-sectional area. Specifically, the area decreased with 40% vs. 10% chuck grip force when the wrist was in 30° ulnar deviation; however, there were no changes in 0° neutral and 15° radial deviation.
Overall, we demonstrated that forceful chuck gripping in deviated wrist positions influenced carpal tunnel dynamics, resulting in both migratory and morphological changes to the median nerve. These changes may, in turn, increase local strain and stress with adjacent structures in the carpal tunnel. Future studies mapping contact stress between structures may further elucidate injury development of work-related carpal tunnel syndrome.
我们同时评估正中神经的移动和变形情况，以更好地了解职业风险因素对腕管动力学的影响，包括强力夹握和手腕偏斜姿势。
14名惯用右手的健康参与者在6种实验条件下进行夹握操作：两种相对用力水平（最大自主用力的10%和40%）；三种手腕姿势（15°桡侧偏斜、0°中立位、30°尺侧偏斜）。使用测力传感器测量夹握力，同时通过超声在腕部远侧横纹处对腕管的横截面积进行成像。在ImageJ中分析正中神经的图像，以评估横截面积、圆形度、宽度和高度，以及前后轴和内外侧轴上的移动情况。
我们发现手腕偏斜姿势对前后向和内外侧移动均有主要影响，最大的神经移动发生在30°尺侧偏斜时。夹握力和手腕偏斜姿势对横截面积也存在显著交互作用。具体而言，当手腕处于30°尺侧偏斜时，与10%夹握力相比，40%夹握力时横截面积减小；然而，在0°中立位和15°桡侧偏斜时没有变化。
总体而言，我们证明了在手腕偏斜姿势下进行强力夹握会影响腕管动力学，导致正中神经出现移动和形态变化。这些变化反过来可能会增加腕管内相邻结构的局部应变和应力。未来绘制结构间接触应力的研究可能会进一步阐明与工作相关的腕管综合征的损伤发展情况。
