Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA.
Med Sci Sports Exerc. 2020 Jan;52(1):105-111. doi: 10.1249/MSS.0000000000002093.
Individuals who are obese, and older individuals, exhibit gait alterations that may result, in part, from walking with greater effort relative to their maximum strength capacity. The goal of this study was to investigate obesity-related and age-related differences in relative effort during gait.
Four groups of women completed the study, including 10 younger healthy-weight, 10 younger obese, 10 older healthy-weight, and 9 older obese women. The protocol included strength measurements at the hip, knee, and ankle in both flexion and extension, and gait trials under self-selected and constrained (1.5 m·s gait speed and 0.65-m step length) conditions. Relative effort was calculated as the ratio of joint torques during gait, and strength from a subject-specific model that predicted strength as a function of joint angle.
Relative effort during self-selected gait was higher among women who were obese in knee extension (P = 0.028) and ankle plantar flexion (P = 0.013). Although both joint torques and strength were higher among women who were obese, these increases in relative effort were attributed to greater obesity-related increases in joint torques than strength. Relative effort was also higher among older women in hip flexion (P < 0.001) and knee extension (P = 0.008), and attributed to age-related strength loss. Results were generally similar between self-selected and constrained gait, indicating the greater relative effort among women who were obese and older women was not attributed to differences in gait spatiotemporal characteristics.
Women who were obese, as well as older women, walk with greater relative effort. These results may help explain the compromised walking ability among these individuals.
肥胖者和老年人的步态发生改变，这可能部分归因于与最大力量能力相比，他们行走时需要付出更大的努力。本研究的目的是探讨肥胖和年龄相关的步态中相对努力的差异。
共有四组女性完成了本研究，包括 10 名年轻健康体重女性、10 名年轻肥胖女性、10 名年长健康体重女性和 9 名年长肥胖女性。方案包括髋关节、膝关节和踝关节在屈伸两个方向的力量测量，以及在自主选择和约束（1.5m·s 的步行速度和 0.65m 的步长）条件下的步态试验。相对努力是通过步态时的关节扭矩与特定于个体的模型预测的作为关节角度函数的力量的比值来计算的。
在自主选择步态中，肥胖女性在膝关节伸展（P = 0.028）和踝关节跖屈（P = 0.013）时的相对努力更高。尽管肥胖女性的关节扭矩和力量都更高，但这些相对努力的增加归因于关节扭矩的肥胖相关性增加大于力量的增加。在髋关节屈曲（P < 0.001）和膝关节伸展（P = 0.008）中，老年女性的相对努力也更高，这归因于与年龄相关的力量损失。自主选择和约束步态的结果基本相似，这表明肥胖女性和老年女性的相对努力更高不是由于步态时空特征的差异造成的。
肥胖女性以及老年女性的行走需要付出更大的相对努力。这些结果可能有助于解释这些个体行走能力受损的原因。
