Department of Industrial and Systems Engineering, Texas A&M University, College Station, TX 77843.
Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843.
Proc Natl Acad Sci U S A. 2024 Aug 20;121(34):e2401874121. doi: 10.1073/pnas.2401874121. Epub 2024 Aug 12.
The human neck is a unique mechanical structure, highly flexible but fatigue prone. The rising prevalence of neck pain and chronic injuries has been attributed to increasing exposure to fatigue loading in activities such as prolonged sedentary work and overuse of electronic devices. However, a causal relationship between fatigue and musculoskeletal mechanical changes remains elusive. This work aimed to establish this relationship through a unique experiment design, inspired by a cantilever beam mechanical model of the neck, and an orchestrated deployment of advanced motion-force measurement technologies including dynamic stereo-radiographic imaging. As a group of 24 subjects performed sustained-till-exhaustion neck exertions in varied positions-neutral, extended, and flexed, their cervical spine musculoskeletal responses were measured. Data verified the occurrence of fatigue and revealed fatigue-induced neck deflection which increased cervical lordosis or kyphosis by 4-5° to 11°, depending on the neck position. This finding and its interpretations render a renewed understanding of muscle fatigue from a more unified motor control perspective as well as profound implications on neck pain and injury prevention.
人体颈部是一个独特的机械结构，高度灵活但容易疲劳。颈部疼痛和慢性损伤的患病率不断上升，这被归因于在长时间久坐工作和过度使用电子设备等活动中越来越多地暴露于疲劳负荷。然而，疲劳与肌肉骨骼机械变化之间的因果关系仍然难以捉摸。这项工作旨在通过一个独特的实验设计来建立这种关系，该设计受到颈部悬臂梁机械模型的启发，并协调部署了先进的运动力测量技术，包括动态立体射线照相成像。当一组 24 名受试者在不同位置（中立、伸展和弯曲）进行持续至疲劳的颈部用力时，测量了他们的颈椎肌肉骨骼反应。数据验证了疲劳的发生，并揭示了疲劳引起的颈部挠度，这导致颈椎前凸或后凸增加了 4-5°至 11°，具体取决于颈部位置。这一发现及其解释从更统一的运动控制角度重新理解了肌肉疲劳，对颈部疼痛和损伤预防也有深远的影响。
