Štefan Andro, Kasović Mario, Štefan Lovro
Department of General and Applied Kinesiology, Faculty of Kinesiology, University of Zagreb, Zagreb 10 000, Croatia.
Department of Physical Activities and Health Sciences, Faculty of Sport Studies, Masaryk University, Brno 625 00, Czech Republic.
Mil Med. 2025 Jan 16;190(1-2):e259-e265. doi: 10.1093/milmed/usae358.
Although the effects of carrying loads on gait biomechanics have been well-documented, to date, little evidence has been provided whether such loads may impact spatial and temporal gait asymmetries under the different foot regions. Therefore, the main purpose of the study was to examine the effects of carrying a standardized police equipment on spatiotemporal gait parameters.
In this population-based study, participants were 845 first-year police recruits (age: 21.2 ± 2.3 years; height: 178.1 ± 10.2 cm; weight: 78.4 ± 11.3 kg; body mass index: 24.7 ± 3.2 kg/m2; 609 men and 236 women; 72.1% men and 27.9% women) measured in 2 conditions: (i) "no load" and (ii) "a 3.5 kg load." Spatiotemporal gait parameters were derived from the FDM Zebris pressure platform. Asymmetry was calculated as (xright-xleft)/0.5*(xright + xleft)*100%, where "x" represented a given parameter being calculated and a value closer to 0 denoted greater symmetry.
When compared to "no load" condition, a standardized 3.5 kg/7.7 lb load significantly increased asymmetries in spatial gait parameters as follows: gait phases of stance (mean diff. = 1.05), load response (mean diff. = 0.31), single limb support (mean diff. = 0.56), pre-swing (mean diff. = 0.22), and swing (mean diff. = 0.90) phase, while no significant asymmetries in foot rotation, step, and stride length were observed. For temporal gait parameters, we observed significant asymmetries in step time (mean diff. = -0.01), while no differences in cadence and gait speed were shown.
The findings indicate that the additional load of 3.5 kg/7.7 lb is more likely to increase asymmetries in spatial gait cycle components, opposed to temporal parameters. Thus, external police load may have hazardous effects in increasing overall body asymmetry, which may lead to a higher injury risk and a decreased performance for completing specific everyday tasks.
尽管负重对步态生物力学的影响已有充分记录，但迄今为止，几乎没有证据表明这种负重是否会在不同足部区域影响空间和时间步态不对称性。因此，本研究的主要目的是检验携带标准化警用装备对时空步态参数的影响。
在这项基于人群的研究中，参与者为845名新入职的警察（年龄：21.2±2.3岁；身高：178.1±10.2厘米；体重：78.4±11.3千克；体重指数：24.7±3.2千克/平方米；男性609名，女性236名；男性占72.1%，女性占27.9%），在两种条件下进行测量：（i）“无负重”和（ii）“3.5千克负重”。时空步态参数由FDM Zebris压力平台得出。不对称性计算为（x右 - x左）/0.5×（x右 + x左）×100%，其中“x”代表正在计算的给定参数，值越接近0表示对称性越高。
与“无负重”条件相比，3.5千克/7.7磅的标准化负重显著增加了空间步态参数的不对称性，如下所示：站立期步态阶段（平均差异 = 1.05）、负重反应期（平均差异 = 0.31）、单腿支撑期（平均差异 = 0.56）、摆动前期（平均差异 = 0.22）和摆动期（平均差异 = 0.90）阶段，而在足部旋转、步长和步幅方面未观察到显著的不对称性。对于时间步态参数，我们观察到步时存在显著的不对称性（平均差异 = -0.01），而在步频和步态速度方面未显示出差异。
研究结果表明，3.5千克/7.7磅的额外负重更有可能增加空间步态周期组成部分的不对称性，而不是时间参数。因此，外部警用负重可能对增加全身不对称性具有有害影响，这可能导致更高的受伤风险以及完成特定日常任务的能力下降。
