Biomechanical and metabolic effects of varying backpack loading on simulated marching
Biomechanical and metabolic effects of varying backpack loading on simulated marching
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DOI：
10.1080/001401300184413
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发表时间：
2000-03-01
期刊：
影响因子：
2.4
通讯作者：
Simon, SR
中科院分区：
文献类型：
--
作者：
Quesada, PM;Mengelkoch, LJ;Simon, SR
12名健康的男性陆军新兵进行了三次，40分钟的跑步机行军6公里/小时，在三个负荷运输条件：0%体重（BW）的背包负荷，15%体重负荷和30%体重负荷。运动学和动力学数据，获得之前和之后，立即每个跑步机游行，计算踝关节，膝关节和髋关节的旋转和时刻。在行军过程中连续收集代谢数据（摄氧量（V）over dot O-2）、呼气通气量（（V over dot）E）、呼吸交换率（RER））、心率（HR）和主观劳累度（RPE）。在整个游行期间，观察到各负荷之间（V/点）O-2、HR和（V）/点E）的显著差异（p小于或等于0.05）。在40 min时，0%BW、15%BW和30%BW负荷的相对能量消耗分别为30、36和41%O（2）max。在行军过程中的RPE反应显着不同，只有30%-BW负载，并大于0%-BW和15%-BW负载的反应。在跑步机行军（行军前）之前的负重试验期间，内伸、髋关节伸展、膝关节伸展和脚踝跖屈力矩的峰值随着背包负荷的增加而增加。相对于0%BW负荷，由于15%BW和30%BW负荷，行军前膝关节力矩的百分比增加显著大于行军前髋关节伸展和跖屈力矩的百分比增加。在所有载荷下，髋关节伸展和踝关节跖屈力矩的行军前和行军后峰值相似，而在15%-BW和30%-BW载荷下，观察到膝关节伸展力矩峰值从行军前到行军后显著下降。行军前的关节负荷数据表明，膝盖可能会影响实质性的补偿，在背包装载行军，也许是为了减弱冲击或减少其他地方的负荷。然而，行军后动力学数据（特别是在15%-BW和30%-BW负荷下）表明，这种膝关节力学并不持久，并表明在行军结束前可能发生过度的膝关节伸肌疲劳，即使在15%-BW和30%-BW负荷下的总体代谢反应保持在一般推荐的限度内，以防止长时间工作期间的疲劳。
Twelve healthy, male Army recruits performed three, 40-min treadmill marches at 6 km/h, under three load carriage conditions: 0%-body weight (BW) backpack load, 15%-BW load and 30%-BW load. Kinematic and kinetic data were obtained, immediately before and after each treadmill march, for computing ankle, knee and hip joint rotations and moments. Metabolic data (oxygen uptake ((V) over dot O-2), expired ventilation ((V over dot) E), respiratory exchange ratio (RER)), heart rate (HR) and ratings of perceived exertion (RPE) were collected continuously during marching. Significant differences (p less than or equal to 0.05) were observed between each load for (V over dot) O-2, HR and (V) over dot E)throughout the marches. At 40 min, relative energy costs for 0%-BW, 15%-BW and 30%-BW loads were 30, 36 and 41% ((V over dot) O(2)max, respectively. RPE responses during marching significantly differed for only the 30%-BW load and were greater than responses at 0%-BW and 15%-BW loads. During load carriage trials prior to treadmill marches (pre-march), peaks in internal, hip extension, knee extension and ankle plantar flexion moments increased with increasing backpack load. Relative to 0%-BW load, percentage increases in knee moments, due to 15%-BW and 30%-BW loads, pre-march, were substantially larger than the percentage increases for hip extension and plantar flexion moments, pre-march. Pre-march and post-march peaks in hip extension and ankle plantar flexion moments were similar with all loads, while notable pre-march to post-march declines were observed for knee extension moment peaks, at 15%-BW and 30%-BW load. Pre-march joint loading data suggests that the knee may be effecting substantial compensations during backpack loaded marching, perhaps to attenuate shock or reduce load elsewhere. Post-march kinetic data (particularly at 15%-BW and 30%-BW load), however, indicates that such knee mechanics were not sustained and suggests that excessive knee extensor fatigue may occur prior to march end, even though overall metabolic responses, at 15%-BW and 30%-BW load, remained within generally recommended limits to prevent fatigue during prolonged work.