Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA.
Gene and Linda Voiland School of Chemical and Bioengineering, Washington State University, Pullman, WA, 99164-6515, USA.
Ann Biomed Eng. 2021 Sep;49(9):2260-2272. doi: 10.1007/s10439-021-02757-4. Epub 2021 Mar 25.
Mild traumatic brain injury (mTBI) and whiplash-associated disorder are the most common head and neck injuries and result from a sudden head or body acceleration. The head and neck injury potential is correlated with the awareness, level of muscle activation, and posture changes at the time of the perturbation. Environmental acoustic stimuli or a warning system can influence muscle activation and posture during a head perturbation. In this study, different acoustic stimuli, including Non-Directional, Directional, and Startle, were provided 1000 ms before a head impact, and the amplitude and timing of cervical muscle electromyographic (EMG) data were characterized based on the type of warning. The startle warning resulted in 49% faster and 80% greater EMG amplitude compared to the Directional and Non-Directional warnings after warning and before the impact. The post-impact peak EMG amplitudes in Unwarned trials were lower by 18 and 21% in the retraction and rebound muscle groups, respectively, compared to any of the warned conditions. When there was no warning before the impact, the retraction and rebound muscle groups also reached their maximum activation 38 and 54 ms sooner, respectively, compared to the warned trials. Based on these results, the intensity and complexity of information that a warning sound carries change the muscle response before and after a head impact and has implications for injury potential.
轻度创伤性脑损伤（mTBI）和挥鞭伤相关疾病是最常见的头部和颈部损伤，由头部或身体的突然加速引起。头部和颈部损伤的潜在风险与头部受到干扰时的意识、肌肉激活水平和姿势变化有关。环境声刺激或预警系统可以影响头部受到干扰时的肌肉激活和姿势。在这项研究中，在头部受到冲击前 1000 毫秒提供了不同的声刺激，包括无方向、有方向和惊跳，根据警告的类型描述了颈椎肌肌电图（EMG）数据的幅度和时间。与有方向和无方向警告相比，惊跳警告在警告后和冲击前使 EMG 幅度分别快 49%和大 80%。与任何警告条件相比，在未受警告的试验中，回缩和回弹肌肉群的冲击后峰值 EMG 幅度分别低 18%和 21%。当冲击前没有警告时，回缩和回弹肌肉群的最大激活时间也分别比受警告的试验提前了 38 和 54 毫秒。基于这些结果，警告声所携带的信息的强度和复杂性改变了头部受到冲击前后的肌肉反应，对损伤的潜在风险有影响。
