LaBiodin Biodynamics Laboratory, School of Physical Education, Physiotherapy and Dance, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Department of Public Health, Experimental Medicine and Forensic Sciences, University of Pavia, Pavia, Italy.
Exp Physiol. 2023 Nov;108(11):1400-1408. doi: 10.1113/EP091408. Epub 2023 Sep 18.
The mechanical and metabolic responses of walking by obese children are not yet well understood. The objectives of this study were (1) to compare the pendular mechanism (recovery, phase shift by α and β values, and ratio between forward and vertical mechanical work), the maximum possible elastic energy usage and the bilateral coordination during walking between non-obese and obese children, and (2) to verify if the bilateral coordination could contribute to understanding the pendular mechanism and elastic energy usage in these populations. Nine obese (six female, 8.7 ± 0.5 years, 1.38 ± 0.04 m, 44.4 ± 6.3 kg and 24.1 ± 3.50 kg/m ) and eight non-obese (four female, 7.4 ± 0.5 years, 1.31 ± 0.08 m, 26.6 ± 2.1 kg and 16.4 ± 1.40 kg/m ) children were analysed during walking on a treadmill at five speeds: 1, 2, 3, 4 and 5 km/h. The results indicated that although the mechanical energy response of the centre of mass during walking is similar between obese and non-obese children, the obese children showed a lower pendulum-like mechanism and greater elastic energy usage during level walking. Therefore, obese children seem to use more elastic energy during walking compared to non-obese children, which may be related to their apparent higher positive work production during the double support phase. Finally, bilateral coordination presented high values at slow speeds in both groups and requires further attention due to its association with falls. NEW FINDINGS: What is the central question of this study? Are there any differences of the pendular and elastic mechanisms and bilateral coordination during walking between non-obese and obese children? What is the main finding and its importance? To our knowledge, this study is the first to analyse the mechanical energy usage and the bilateral coordination of obese and non-obese children during walking. Obese children had a lower pendular recovery mechanism and used more elastic energy compared to non-obese children. The bilateral coordination was higher at slow speeds in both groups and requires further attention due to its association with falls.
肥胖儿童行走时的力学和代谢反应尚不清楚。本研究的目的是：(1) 比较非肥胖和肥胖儿童行走时的摆动机制（恢复、α 和 β 值的相位偏移以及前后向和垂直向机械功的比值）、最大弹性能量利用和双侧协调；(2) 验证双侧协调是否有助于理解这两种人群的摆动机制和弹性能量利用。本研究纳入了 9 名肥胖儿童（6 名女性，年龄 8.7±0.5 岁，身高 1.38±0.04m，体重 44.4±6.3kg，体质量指数 24.1±3.50kg/m ）和 8 名非肥胖儿童（4 名女性，年龄 7.4±0.5 岁，身高 1.31±0.08m，体重 26.6±2.1kg，体质量指数 16.4±1.40kg/m ），在跑步机上以 5 种速度（1、2、3、4 和 5km/h）行走时进行分析。结果表明，虽然肥胖和非肥胖儿童行走时的质心力学能量反应相似，但肥胖儿童在水平行走时表现出较低的钟摆样机制和更大的弹性能量利用。因此，与非肥胖儿童相比，肥胖儿童在行走时似乎利用更多的弹性能量，这可能与他们在双支撑阶段明显更高的正功产生有关。最后，两组在低速时的双侧协调均呈现出较高的数值，需要进一步关注，因为其与跌倒有关。新发现：本研究的核心问题是什么？非肥胖和肥胖儿童在行走时的摆动和弹性机制以及双侧协调是否存在差异？主要发现及其重要性是什么？据我们所知，本研究首次分析了肥胖和非肥胖儿童行走时的机械能量利用和双侧协调。肥胖儿童的摆动恢复机制较低，与非肥胖儿童相比，他们利用更多的弹性能量。两组在低速时的双侧协调均较高，需要进一步关注，因为其与跌倒有关。
