Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA.
Spaulding National Running Center, Spaulding Rehabilitation Hospital, Cambridge, Massachusetts, USA.
Eur J Sport Sci. 2024 Jun;24(6):740-749. doi: 10.1002/ejsc.12091. Epub 2024 Mar 20.
Lower extremity injuries are prevalent in military trainees, especially in female and older trainees. Modifiable factors that lead to higher injury risk in these subgroups are not clear. The purpose of this study was to identify whether external loading variables during military-relevant tasks differ by age and sex in U.S. Army trainees. Data was collected on 915 trainees in the first week of Basic Combat Training. Participants performed running and ruck marching (walking with 18.1 kg pack) on a treadmill, as well as double-/single-leg drop landings. Variables included: vertical force loading rates, vertical stiffness, first peak vertical forces, peak vertical and resultant tibial accelerations. Comparisons were made between sexes and age groups (young, ≤19 years; middle, 20-24 years; older, ≥25 years). Significant main effects of sex were found, with females showing higher vertical loading rates during ruck marching, and peak tibial accelerations during running and ruck marching (p ≤ 0.03). Males showed higher vertical stiffness during running and peak vertical tibial accelerations during drop landings (p < 0.01). A main effect of age was found for vertical loading rates during running (p = 0.03), however no significant pairwise differences were found between age groups. These findings suggest that higher external loading may contribute to higher overall injury rates in female trainees. Further, higher stiffness during running may contribute to specific injuries, such as Achilles Tendinopathy, that are more prevalent in males. The lack of differences between age groups suggests that other factors contribute more to higher injury rates in older trainees.
下肢损伤在军事受训人员中很常见，尤其是女性和年龄较大的受训人员。导致这些亚组受伤风险较高的可改变因素尚不清楚。本研究的目的是确定在美国陆军受训人员中，与军事相关任务期间的外部加载变量是否因年龄和性别而有所不同。在基础战斗训练的第一周收集了 915 名受训人员的数据。参与者在跑步机上进行跑步和背负行军（携带 18.1 公斤背包行走），以及双腿/单腿跳下着陆。变量包括：垂直力加载率、垂直刚度、第一峰值垂直力、峰值垂直和合成胫骨加速度。比较了性别和年龄组（年轻，≤19 岁；中年，20-24 岁；老年，≥25 岁）之间的差异。发现性别存在显著的主要影响，女性在背负行军时的垂直加载率较高，在跑步和背负行军时的峰值胫骨加速度较高（p≤0.03）。男性在跑步和跳下着陆时表现出较高的垂直刚度和峰值垂直胫骨加速度（p<0.01）。在跑步时的垂直加载率发现存在年龄的主要影响（p=0.03），但在年龄组之间没有发现显著的差异。这些发现表明，较高的外部加载可能导致女性受训人员的总体受伤率较高。此外，跑步时较高的刚度可能导致特定的损伤，例如更常见于男性的跟腱炎。年龄组之间没有差异表明，其他因素对老年受训人员较高的受伤率有更大的影响。
