Jadischke Ron, Viano David C, McCarthy Joe, King Albert I
McCarthy Engineering, Windsor, Ontario, Canada.
Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA.
BMJ Open Sport Exerc Med. 2018 Oct 16;4(1):e000362. doi: 10.1136/bmjsem-2018-000362. eCollection 2018.
Most biomechanical research on brain injury focuses on direct blows to the head. There are a few older studies that indicate craniocervical stretch could be a factor in concussion by causing strain in the upper spinal cord and brainstem. The objectives of this study are to assess the biomechanical response and estimate the strain in the upper cervical spine and brainstem from primary impact to the chest in American football.
Impact testing was conducted to the chest of a stationary unhelmeted and helmeted anthropomorphic test device (ATD) as well as the laboratory reconstruction of two NFL game collisions resulting in concussion. A finite element (FE) study was also conducted to estimate the elongation of the cervical spine under tensile and flexion loading conditions.
The helmeted ATD had a 40% (t=9.84, p<0.001) increase in neck tensile force and an 8% (t=7.267, p<0.001) increase in neck flexion angle when compared with an unhelmeted ATD. The case studies indicated that the neck tension in the injured players exceeded tolerable levels from volunteer studies. The neck tension was combined with flexion of the head relative to the torso. The FE analysis, combined with a spinal cord coupling ratio, estimated that the strain along the axis of the upper cervical spinal cord and brainstem was 10%-20% for the combined flexion and tension loading in the two cases presented.
Strain in the upper spinal cord and brainstem from neck tension is a factor in concussion.
大多数关于脑损伤的生物力学研究都集中在头部的直接撞击上。有一些较早的研究表明，颅颈拉伸可能是导致脑震荡的一个因素，因为它会在上脊髓和脑干中引起应变。本研究的目的是评估生物力学反应，并估计美式橄榄球运动中胸部受到原发性撞击时上颈椎和脑干的应变。
对一个静止的未戴头盔和戴头盔的人体模型试验装置（ATD）的胸部进行了撞击测试，以及对两场导致脑震荡的美国国家橄榄球联盟（NFL）比赛碰撞进行了实验室重建。还进行了一项有限元（FE）研究，以估计颈椎在拉伸和屈曲载荷条件下的伸长情况。
与未戴头盔的ATD相比，戴头盔的ATD颈部拉力增加了40%（t=9.84，p<0.001），颈部屈曲角度增加了8%（t=7.267，p<0.001）。案例研究表明，受伤球员的颈部张力超过了志愿者研究中的可耐受水平。颈部张力与头部相对于躯干的屈曲相结合。有限元分析结合脊髓耦合比估计，在给出的两个案例中，上颈椎和脑干轴线上的应变在屈曲和拉伸联合载荷作用下为10%-20%。
颈部张力导致的上脊髓和脑干应变是脑震荡的一个因素。
