Rubio Jose E, Tong Junfei, Sundaramurthy Aravind, Subramani Adhitya V, Kote Vivek Bhaskar, Baggaley Michael, Edwards W Brent, Reifman Jaques
Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.
The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States.
Front Bioeng Biotechnol. 2023 Oct 3;11:1250937. doi: 10.3389/fbioe.2023.1250937. eCollection 2023.
During U.S. Army basic combat training (BCT), women are more prone to lower-extremity musculoskeletal injuries, including stress fracture (SF) of the tibia, with injury rates two to four times higher than those in men. There is evidence to suggest that the different injury rates are, in part, due to sex-specific differences in running biomechanics, including lower-extremity joint kinematics and kinetics, which are not fully understood, particularly when running with external load. To address this knowledge gap, we collected computed tomography images and motion-capture data from 41 young, healthy adults (20 women and 21 men) running on an instrumented treadmill at 3.0 m/s with loads of 0.0 kg, 11.3 kg, or 22.7 kg. Using individualized computational models, we quantified the running biomechanics and estimated tibial SF risk over 10 weeks of BCT, for each load condition. Across all load conditions, compared to men, women had a significantly smaller flexion angle at the trunk (16.9%-24.6%) but larger flexion angles at the ankle (14.0%-14.7%). Under load-carriage conditions, women had a larger flexion angle at the hip (17.7%-23.5%). In addition, women had a significantly smaller hip extension moment (11.8%-20.0%) and ankle plantarflexion moment (10.2%-14.3%), but larger joint reaction forces (JRFs) at the hip (16.1%-22.0%), knee (9.1%-14.2%), and ankle (8.2%-12.9%). Consequently, we found that women had a greater increase in tibial strain and SF risk than men as load increases, indicating higher susceptibility to injuries. When load carriage increased from 0.0 kg to 22.7 kg, SF risk increased by about 250% in women but only 133% in men. These results provide quantitative evidence to support the Army's new training and testing doctrine, as it shifts to a more personalized approach that shall account for sex and individual differences.
在美国陆军基础战斗训练（BCT）期间，女性更容易发生下肢肌肉骨骼损伤，包括胫骨应力性骨折（SF），其损伤率比男性高两到四倍。有证据表明，不同的损伤率部分归因于跑步生物力学方面的性别差异，包括下肢关节运动学和动力学，但这些差异尚未完全明确，尤其是在负重跑步时。为填补这一知识空白，我们收集了41名年轻健康成年人（20名女性和21名男性）在装有仪器的跑步机上以3.0米/秒的速度跑步时的计算机断层扫描图像和运动捕捉数据，负重分别为0.0千克、11.3千克或22.7千克。我们使用个性化计算模型，对每种负重条件下BCT的10周内的跑步生物力学进行了量化，并估计了胫骨应力性骨折风险。在所有负重条件下，与男性相比，女性的躯干屈曲角度明显更小（16.9%-24.6%），但踝关节屈曲角度更大（14.0%-14.7%）。在负重条件下，女性的髋关节屈曲角度更大（17.7%-23.5%）。此外，女性的髋关节伸展力矩明显更小（11.8%-20.0%），踝关节跖屈力矩更小（10.2%-14.3%），但髋关节（16.1%-22.0%）、膝关节（9.1%-14.2%）和踝关节（8.2%-12.9%）的关节反应力更大。因此，我们发现随着负重增加，女性胫骨应变和应力性骨折风险的增加幅度比男性更大，表明女性更容易受伤。当负重从0.0千克增加到22.7千克时，女性的应力性骨折风险增加了约250%，而男性仅增加了133%。这些结果提供了定量证据，以支持陆军新的训练和测试原则，因为它转向了一种更个性化的方法，该方法应考虑性别和个体差异。
