Zabihhosseinian Mahboobeh, Yielder Paul, Holmes Michael W R, Murphy Bernadette
Faculty of Health Sciences, University of Ontario Institute of Technology, 2000 Simcoe St. North, Oshawa, ON L1H 7K4, Canada.
Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada.
J Electromyogr Kinesiol. 2019 Aug;47:1-9. doi: 10.1016/j.jelekin.2019.04.001. Epub 2019 Apr 10.
Altered afferent input from the neck due to fatigue alters upper limb proprioception and is likely to impact upper limb performance accuracy. This study examined the effect of cervical extensor muscle (CEM) fatigue on eye-hand tracking accuracy in healthy participants. Twenty-four healthy right-handed individuals were randomly assigned to either a control or CEM fatigue group. Each participant performed a tracking task which required shoulder rotation to move a circular object to a square target on a touchscreen computer. The task was performed with vision of the target and with the target hidden. A prone lying position, CEM fatigue protocol required participants to hold a 2 kg weight against gravity with their head in a neutral posture. The control intervention rested for 5 min, in a prone position, with the head supported in a neutral posture. Participants performed 3 trials with vision and 3 without at 5 different time points: (1) pre-intervention (fatigue or control), (2) immediately post-intervention, (3) 5 min, (4) 10 min, and (5) 20 min post-intervention. There were significant differences between the target with vision and the hidden condition for both groups between pre- and post-fatigue trials in angle of trajectory (p = 0.0001), and distance from release point to the target (p = 0.0001). Significant differences occurred in the hidden target condition for the fatigue group immediately post fatigue (p = 0.018) for distance from release to the target. Neck muscle fatigue reduced the accuracy of an upper limb tracking task to a hidden target, suggesting that altered afferent input from the neck due to fatigue may impair body schema and result in decreased upper limb performance accuracy.
由于疲劳导致来自颈部的传入输入改变，会改变上肢本体感觉，并可能影响上肢运动表现的准确性。本研究调查了健康受试者中颈伸肌（CEM）疲劳对眼手追踪准确性的影响。24名健康的右利手个体被随机分配到对照组或CEM疲劳组。每位受试者执行一项追踪任务，该任务要求通过肩部旋转将一个圆形物体移动到触摸屏电脑上的方形目标处。该任务分别在目标可见和目标隐藏的情况下进行。采用俯卧位，CEM疲劳方案要求受试者头部保持中立姿势，对抗重力托举一个2千克的重物。对照干预是在俯卧位休息5分钟，头部以中立姿势得到支撑。受试者在5个不同时间点分别进行了3次目标可见和3次目标隐藏的试验：（1）干预前（疲劳或对照），（2）干预后即刻，（3）5分钟后，（4）10分钟后，以及（5）20分钟后。在疲劳试验前后，两组在目标可见和隐藏条件下，轨迹角度（p = 0.0001）以及从释放点到目标的距离（p = 0.0001）方面均存在显著差异。在疲劳组中，疲劳后即刻在隐藏目标条件下，从释放到目标的距离出现了显著差异（p = 0.018）。颈部肌肉疲劳降低了上肢追踪隐藏目标任务的准确性，这表明由于疲劳导致来自颈部的传入输入改变可能会损害身体图式，并导致上肢运动表现准确性下降。
