Gold Coast Orthopaedics Research, Engineering and Education Alliance, Menzies Health Institute Queensland, School of Allied Health Sciences, Griffith University, Southport, Queensland, Australia.
Department of Health Professions, Faculty of Medicine and Health Sciences, Macquarie University, New South Wales, Australia.
PLoS One. 2018 Nov 5;13(11):e0206859. doi: 10.1371/journal.pone.0206859. eCollection 2018.
Musculoskeletal injuries (MSI) in the military reduce soldier capability and impose substantial costs. Characterizing biomechanical surrogates of MSI during commonly performed military tasks (e.g., load carriage) is necessary for evaluating the effectiveness of possible interventions to reduce MSI risk. This study determined the effects of body-borne load distribution, load magnitude, and walking speed on tibiofemoral contact forces. Twenty-one Australian Army Reserve soldiers completed a treadmill walking protocol in an unloaded condition and wearing four armor types (standard-issue and three prototypes) with two load configurations (15 and 30 kg) for a total of 8 armor x load ensembles. In each ensemble, participants completed a 5-minute warm-up, and then walked for 10 minutes at both moderate (1.53 m⋅s-1) and fast (1.81 m⋅s-1) speeds. During treadmill walking, three-dimensional kinematics, ground reaction forces, and muscle activity from nine lower-limb muscles were collected in the final minute of each speed. These data were used as inputs into a neuromusculoskeletal model, which estimated medial, lateral and total tibiofemoral contact forces. Repeated measures analyses of variance revealed no differences for any variables between armor types, but peak medial compartment contact forces increased when progressing from moderate to fast walking and with increased load (p<0.001). Acute exposure to load carriage increased estimated tibiofemoral contact forces 10.1 and 19.9% with 15 and 30kg of carried load, respectively, compared to unloaded walking. These results suggest that soldiers carrying loads in excess of 15 kg for prolonged periods could be at greater risk of knee MSI than those with less exposure.
肌肉骨骼损伤（MSI）会降低士兵的作战能力，并造成巨大的经济损失。在评估减少 MSI 风险的可能干预措施的有效性时，需要对常见军事任务（例如负重行军）中 MSI 的生物力学替代指标进行特征描述。本研究旨在确定身体负重分布、负重大小和行走速度对胫股关节接触力的影响。21 名澳大利亚陆军预备役士兵在无负重状态和穿着四种装甲类型（标准和三种原型）并携带两种负载配置（15 和 30 公斤）的情况下完成了跑步机行走方案，共进行了 8 种装甲 x 负载组合。在每个组合中，参与者先进行 5 分钟的热身，然后以中速（1.53 m⋅s-1）和快速（1.81 m⋅s-1）两种速度各行走 10 分钟。在跑步机行走过程中，采集了 9 条下肢肌肉的三维运动学、地面反作用力和肌肉活动数据，每个速度下的最后一分钟采集一次。这些数据被用作神经肌肉骨骼模型的输入，该模型估计了内侧、外侧和总的胫股关节接触力。重复测量方差分析显示，在任何变量方面，不同的装甲类型之间均无差异，但从中速到快速行走以及增加负荷时，内侧关节接触力峰值均会增加（p<0.001）。与无负荷行走相比，携带 15 公斤和 30 公斤的负载时，分别增加了 10.1%和 19.9%的估计胫股关节接触力，表明长时间携带超过 15 公斤的负荷的士兵比那些暴露程度较低的士兵更有可能出现膝关节 MSI。
