Krajewski Kellen T, Johnson Camille C, Mi Qi, Flanagan Shawn D, Anderst William J, Connaboy Christopher
Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Department of Orthopedics, University of Colorado School of Medicine, Aurora, Colorado, USA.
Orthop J Sports Med. 2025 Mar 19;13(3):23259671251322785. doi: 10.1177/23259671251322785. eCollection 2025 Mar.
Military personnel in combat roles observe a high prevalence of knee osteoarthritis. Knee total joint moment (KTJM) and the knee adduction moment percentage contribution (KAM%) of KTJM have been linked to knee osteoarthritis. It is postulated that sex, load carriage, and imposed locomotion patterns such as forced marching (FM) alter mechanics of the knee. The purpose of this study was to determine the effects of "military-relevant" load magnitudes, locomotion patterns, and sex on KTJM and its planar percentage contributions in recruit-aged adults during short-duration gait tasks.
The greatest load magnitude and FM will significantly increase KAM contribution to KTJM compared with lower magnitudes or no load. Additionally, women will exhibit greater KAM contribution to KTJM compared with men regardless of experimental condition.
Controlled laboratory study.
Twenty healthy recruit-aged (18-35 years) adults (10 male, 10 female) executed trials of running and FM with no load (BW), an additional load of 45% of BW, and an additional load of 55% of BW. KTJM was calculated along with each plane of motion percentage contribution: knee flexion moment (KFM%), KAM%, and knee rotation moment (KRM%). A 3 × 2 × 2 mixed model analysis of variance was used to evaluate the effects of load carriage, locomotion pattern, and sex on KTJM, KFM%, KAM%, and KRM% at multiple gait events of stance phase.
FM exhibited a greater ( < .001) KTJM than running at heel strike. Running had greater KAM% ( = .01) and KRM% ( < .001) compared with FM. At midstance, running exhibited greater ( < .001) KTJM than FM for each load condition; however, FM had greater KAM% ( < .001) and KRM% ( = .002) compared with running at peak vertical ground reaction force and midstance. Men exhibited greater KAM% at heel strike ( = .02) independent of locomotion pattern and at midstance ( = .04) for FM.
Load carriage increases KAM% to a magnitude similarly observed in populations with knee osteoarthritis, especially when executing FM. Interestingly, men exhibited greater KAM% than women, suggesting differing strategies to motor execution with relative load carriage.
Screening recruits for greater KAM% during loaded gait tasks may identify individuals in need of specialized training to reduce the risk of knee osteoarthritis development.
担任战斗角色的军事人员中膝关节骨关节炎的患病率很高。膝关节总关节力矩（KTJM）以及KTJM中膝关节内收力矩百分比贡献（KAM%）与膝关节骨关节炎有关。据推测，性别、负重以及诸如强制行军（FM）等特定运动模式会改变膝关节力学。本研究的目的是确定“与军事相关”的负荷大小、运动模式和性别对新兵年龄段成年人在短时间步态任务中KTJM及其平面百分比贡献的影响。
与较低负荷或无负荷相比，最大负荷量和FM将显著增加KAM对KTJM的贡献。此外，无论实验条件如何，女性对KTJM的KAM贡献都将大于男性。
对照实验室研究。
20名健康的新兵年龄段（18 - 35岁）成年人（10名男性，10名女性）进行无负荷（体重BW）、额外负荷为BW的45%以及额外负荷为BW的55%的跑步和FM试验。计算KTJM以及每个运动平面的百分比贡献：膝关节屈曲力矩（KFM%）、KAM%和膝关节旋转力矩（KRM%）。使用3×2×2混合模型方差分析来评估负重、运动模式和性别对站立相多个步态事件中KTJM、KFM%、KAM%和KRM%的影响。
在足跟触地时，FM的KTJM比跑步时更大（P <.001）。与FM相比，跑步时的KAM%（P = 0.01）和KRM%（P <.001）更大。在支撑中期，对于每种负荷条件，跑步时的KTJM比FM时更大（P <.001）；然而，在峰值垂直地面反作用力和支撑中期时，与跑步相比，FM的KAM%（P <.001）和KRM%（P = 0.002）更大。在足跟触地时，无论运动模式如何，男性的KAM%更大（P = 0.02），在FM的支撑中期时也是如此（P = 0.04）。
负重会增加KAM%，达到在膝关节骨关节炎人群中类似观察到的程度，尤其是在执行FM时。有趣的是，男性的KAM%比女性更大，这表明在相对负重情况下运动执行策略存在差异。
在负重步态任务中筛查新兵中较高的KAM%，可能会识别出需要接受专门训练以降低膝关节骨关节炎发病风险的个体。
