Faculty of Health Sciences (Kinesiology), Ontario Tech University, Oshawa, Ontario, Canada; Department of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada.
Faculty of Health Sciences (Kinesiology), Ontario Tech University, Oshawa, Ontario, Canada.
J Electromyogr Kinesiol. 2021 Aug;59:102554. doi: 10.1016/j.jelekin.2021.102554. Epub 2021 Apr 30.
Cervical extensor muscle (CEM) fatigue causes decrements in upper limb proprioceptive accuracy during constrained single-joint tasks. This study used a novel humeral rotation joint position sense (JPS) measurement device to compare JPS accuracy in participants who received acute CEM fatigue vs. non-fatigued controls.
Participants had vision occluded and were passively guided into postures of internal humeral rotation from a baseline posture before and after a CEM fatigue or control protocol. Mixed model repeated measures ANOVAs were used to verify fatigue and compared absolute, constant, and variable JPS error between groups.
CEM fatigue was verified via pre-post reduction in CEM strength, and myoelectric indicators of fatigue. However, between-group comparisons of absolute, constant, and variable JPS error were not statistically significant, despite having large effect sizes.
Contrary to prevailing literature, unconstrained humeral rotation JPS did not appear to be affected by CEM fatigue in this study. However, between-group differences in JPS error were dwarfed by inter-trial variability, which likely arose due to the unconstrained nature of this task, conflating chances for a Type II error. Future research should perform a kinematic analysis of task constraints to highlight potential compensatory mechanisms obscuring significant findings in this otherwise robust effect.
颈部伸肌（CEM）疲劳会导致在受限的单关节任务中上肢本体感觉准确性下降。本研究使用新型肱骨旋转关节位置感（JPS）测量装置，比较了接受急性 CEM 疲劳和非疲劳对照的参与者的 JPS 准确性。
参与者的视力被遮挡，并在接受 CEM 疲劳或对照方案前后，从基线姿势被动引导到内部肱骨旋转姿势。混合模型重复测量方差分析用于验证疲劳，并比较组间的绝对、恒定和可变 JPS 误差。
通过 CEM 力量和疲劳的肌电图指标的前后减少来验证 CEM 疲劳。然而，尽管存在较大的效应量，但绝对、恒定和可变 JPS 误差的组间比较在统计学上并不显著。
与流行的文献相反，在这项研究中，不受限制的肱骨旋转 JPS 似乎不受 CEM 疲劳的影响。然而，JPS 误差的组间差异被试验间变异性所掩盖，这可能是由于该任务不受限制，混淆了发生第二类错误的机会。未来的研究应该对任务约束进行运动学分析，以突出潜在的补偿机制，这些机制掩盖了这一强大效应中的显著发现。
