Department of Kinesiology, Brock University, St. Catharines, Canada.
Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genoa, Italy.
PeerJ. 2022 May 24;10:e13495. doi: 10.7717/peerj.13495. eCollection 2022.
The purpose of this work was to investigate forearm muscle activity and wrist angular displacement during radial and ulnar wrist perturbations across various isometric hand grip demands. Surface electromyography (EMG) was recorded from eight muscles of the upper extremity. A robotic device delivered perturbations to the hand in the radial and ulnar directions across four pre-perturbation grip magnitudes. Angular displacement and time to peak displacement following perturbations were evaluated. Muscle activity was evaluated pre- and post-perturbation. Results showed an inverse relationship between grip force and angular displacement ( ≤ 0.001). Time to peak displacement decreased as grip force increased ( ≤ 0.001). There was an increase in muscle activity with higher grip forces across all muscles both pre-and post-perturbation ( ≤ 0.001) and a greater average muscle activity in ulnar as compared to radial deviation ( = 0.02). This work contributes to the wrist joint stiffness literature by relating wrist angular displacement to grip demands during novel radial/ulnar perturbations and provides insight into neuromuscular control strategies.
本研究旨在探讨在不同等长手握力需求下，桡侧和尺侧腕部偏斜时前臂肌肉活动和腕关节角位移的情况。采用表面肌电图（EMG）记录上肢 8 块肌肉的活动。机器人设备在手的桡侧和尺侧方向上施加偏斜，在 4 个预偏斜握力大小下进行。评估偏斜后的角位移和到达峰值位移的时间。在偏斜前后评估肌肉活动。结果表明，握力与角位移呈负相关（≤0.001）。随着握力的增加，到达峰值位移的时间减少（≤0.001）。在桡侧和尺侧偏斜前后，所有肌肉的肌肉活动都随较高的握力而增加（≤0.001），与桡侧偏斜相比，尺侧偏斜的平均肌肉活动更高（=0.02）。本研究通过在新的桡侧/尺侧偏斜中，将腕关节角位移与握力需求联系起来，为腕关节刚度文献做出了贡献，并为神经肌肉控制策略提供了新的见解。
