Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA.
UPMC Sports Medicine Concussion Program/Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA.
Med Sci Sports Exerc. 2019 Aug;51(8):1619-1625. doi: 10.1249/MSS.0000000000001974.
Concussions are common in military personnel and may result in increased risk of musculoskeletal injury. One plausible explanation for this risk could be that neuromotor deficiencies enhance injury risk after a concussion through altered muscular activation/contraction timing.
To compare military personnel with at least one concussion during the past 1 month to 2 yr (CONCUSSED) to military branch-matched, age-matched, and Special Operations Forces group-matched controls (CONTROL) on physiological, musculoskeletal, and biomechanical performance.
A total of 48 (24 CONCUSSED, 24 CONTROL) male Air Force and Naval Special Warfare Operators age 19 to 34 yr participated in the study. Participants self-reported demographics/injury history and completed the following assessments: 1) physiological-body composition, anaerobic power and capacity, aerobic capacity and lactate threshold; 2) musculoskeletal-lower extremity isokinetic strength testing, including time to peak torque; and 3) biomechanical-single-leg jump and landing task, including landing kinematics of the hip, knee and ankle. A machine learning decision tree algorithm (C5.0) and one-way ANOVA were used to compare the two groups on these outcomes.
Despite nonsignificant differences using ANOVA, the C5.0 algorithm revealed CONCUSSED demonstrated quicker time to peak knee flexion angle during the single-leg landing task (≤0.170 s; CONCUSSED: n = 22 vs CONTROL: n = 14), longer time to peak torque in knee extension isokinetic strength testing (>500 ms; CONCUSSED: n = 18 vs CONTROL: n = 4) and larger knee flexion angle at initial contact (>7.7°; CONCUSSED: n = 18 vs CONTROL: n = 2).
The findings supported the hypothesis that CONCUSSED military personnel would demonstrate altered neuromuscular control in landing strategies and muscular activation. Future research should assess prospectively neuromuscular changes after a concussion and determine if these changes increase risk of subsequent musculoskeletal injuries.
将过去 1 个月至 2 年内至少有 1 次脑震荡的军事人员与军事部门匹配、年龄匹配和特种作战部队分组匹配的对照组（CONTROL）进行比较，评估其生理机能、肌肉骨骼和生物力学表现。
共有 48 名（24 名脑震荡患者，24 名对照组）年龄在 19 至 34 岁的男性空军和海军特种作战人员参与了这项研究。参与者报告了人口统计学/损伤史，并完成了以下评估：1）生理机能-身体成分、无氧功率和容量、有氧能力和乳酸阈；2）肌肉骨骼-下肢等速力量测试，包括达到峰值扭矩的时间；3）生物力学-单腿跳跃和着陆任务，包括髋关节、膝关节和踝关节的着陆运动学。使用机器学习决策树算法（C5.0）和单因素方差分析对两组结果进行比较。
尽管使用方差分析未发现显著差异，但 C5.0 算法显示，在单腿着陆任务中，脑震荡患者的膝关节屈曲角度达到峰值的时间更快（≤0.170 s；脑震荡患者：n=22 对对照组：n=14），膝关节等速力量测试中达到峰值扭矩的时间更长（>500 ms；脑震荡患者：n=18 对对照组：n=4），初始接触时膝关节屈曲角度更大（>7.7°；脑震荡患者：n=18 对对照组：n=2）。
研究结果支持了这样的假设，即脑震荡的军事人员在着陆策略和肌肉激活方面会表现出改变的神经肌肉控制。未来的研究应前瞻性评估脑震荡后的神经肌肉变化，并确定这些变化是否会增加随后肌肉骨骼损伤的风险。
