How do the neck muscles influence head acceleration during sport-associated impact events in high school athletes?

项目摘要/摘要 与运动相关的脑震荡是一种常见而严重的损伤，约有780万名学生运动员参加了 美国每年的高中水平降低脑震荡风险的成功策略及其 在这一人群中产生相关的不利的短期和长期后果将推进 增进健康，减少疾病和残疾，促进儿童充分发展的机会 为健康和富有成效的生活创造潜力。颈部强化运动可能就是这样一种干预。 脖子较小、较弱的运动员被认为有更高的脑震荡风险，因为他们的脖子 在与运动相关的碰撞中，更不能对抗作用在头部的力量，导致更大的 由此产生的净水头加速度。然而，我们对颈部疾病的机制的理解 对头部加速度的影响仍然不完整，这种关系可能会被 运动仍不清楚。这些问题必须在加强颈部锻炼计划之前得到回答 可以优化以降低运动员脑震荡的风险。拟议的机械性前瞻性临床试验将 追求以下具体目标：目标1)确定手动阻力颈强化的效果 在多种模拟运动下，锻炼对颈部力量、颈部肌肉体积和头部净加速度的影响 相关冲击条件；目的2)确定颈部力量和颈部肌肉的相对影响 在模拟运动相关对头和身体的撞击期间，头部净加速度的体积， 无意志性预期的颈肌预收缩为冲击做好准备。实现目标1的方法 将连续重新评估低强度或高强度体力颈部强化练习的效果 程序的关键颈部肌肉属性和净头部加速度在每个冲击条件下。 将对108名高中运动员进行基线评估，并在完成4、8和12项后进行评估 进行为期数周的运动干预，并与参加“肩膀向下”运动的对照组进行比较 锻炼计划不是专门针对颈部的。实现目标2的方法将是比较R2值 使用在有和没有预期颈肌预收缩的情况下收集的基线数据的统计模型 根据颈部力量、颈部肌肉体积或两者来预测头部净加速度。这项研究 预计将建立体力颈部强化练习的剂量-反应关系 颈部力量、颈部肌肉体积和头部净加速度，以及定义 颈部控制头部和身体在有和没有预期颈部的撞击过程中的加速度 肌肉预收缩，为冲击做好准备。这项工作将提供重要的机制洞察如何 颈部肌肉抵抗头部加速，这最终将导致改善颈部强化运动。 面向运动员的节目。通过这样做，这项工作将有助于减少脑震荡的长期目标- 通过开出健颈运动处方来提高相关发病率。

PROJECT SUMMARY/ABSTRACT Sport-related concussion is a common and serious injury in the ~7.8 million student-athletes who compete at the high school level each year in the U.S. A successful strategy for reducing the risk of concussion and its associated adverse short- and long-term consequences in this population would advance the mission of enhancing health, reducing illness and disability, and promoting children’s chances to achieve their full potential for healthy and productive lives. Neck strengthening exercise may represent such an intervention. Athletes with smaller, weaker necks are thought to be at increased risk for concussion because their necks are less able to counter the forces acting on their heads during sport-associated collisions, leading to greater resultant net head accelerations. However, our understanding of the mechanism governing the neck’s influence over head acceleration remains incomplete, and the potential for this relationship to be modified by exercise remains unclear. These questions must be answered before neck strengthening exercise programs can be optimized to reduce athletes’ risk of concussion. The proposed mechanistic prospective clinical trial will pursue the following specific aims: AIM 1) to determine the effect of manual resistance neck strengthening exercise on neck strength, cervical muscle volume, and net head acceleration under multiple simulated sport- associated impact conditions; AIM 2) to determine the relative influences of neck strength and cervical muscle volume on net head acceleration during simulated sport-associated impacts to the head and body, with and without volitional anticipatory cervical muscle pre-contraction to brace for the impact. The approach to AIM 1 will be to serially reassess the effects of a low or high intensity manual resistance neck strengthening exercise program on key cervical muscle attributes and net head acceleration under each impact condition. Assessments will be performed in 108 high school athletes at baseline and upon completion of 4, 8, and 12 weeks of the exercise intervention, with comparison to a control group participating in a “shoulders-down” exercise program not specifically targeting the neck. The approach to AIM 2 will be to compare the R2 values of statistical models using baseline data collected with and without anticipatory cervical muscle pre-contraction to predict net head acceleration based on either neck strength, cervical muscle volume, or both. This research is expected to establish dose-response relationships for manual resistance neck strengthening exercise on neck strength, cervical muscle volume, and net head acceleration, as well as define the mechanism by which the neck controls head acceleration during impacts to the head and body with and without anticipatory cervical muscle pre-contraction to brace for the impact. This work will provide important mechanistic insight about how the cervical muscles resist head acceleration that will ultimately lead to improved neck strengthening exercise programs for athletes. In doing so, this work will contribute to the long term objective of reducing concussion- related morbidity through the prescription of neck strengthening exercise.