Gao Ying, Haapala Eero A, Vanhala Anssi, Sääkslahti Arja, Rantakokko Merja, Laukkanen Arto, Pesola Arto J, Rantalainen Timo, Finni Taija
Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
Front Physiol. 2019 Aug 7;10:997. doi: 10.3389/fphys.2019.00997. eCollection 2019.
We investigated the ability of energy expenditure, movement sensing, and muscle activity to discriminate sedentary and non-sedentary activities in children. Thirty-five 7-11-year-old children participated in the study. Simultaneous assessment of oxygen uptake (V̇O), triaxial accelerometry, and thigh muscle electromyography (EMG) were performed during eight different sedentary and non-sedentary activities including lying down, sitting-, standing-, and walking-related activities, which were performed in a random order. Mean values of V̇O, accelerometry, and EMG from the concurrent 2 min epochs during each activity were computed. Resting energy expenditure (REE) was measured during 30 min supine rest. Directly measured metabolic equivalent of tasks (METs, V̇O in activities/V̇O in REE) were calculated for each activity. Mean amplitude deviation (MAD) was computed for accelerometry. EMG was normalized for mean muscle activity during self-paced walking. The classification accuracy of METs, MAD, and EMG to discriminate sedentary activities from physical activities was investigated by receiver operating characteristic curves and optimal cut-offs based on maximal sensitivity and specificity. Mean (SD) REE was 5.0 ± 0.8 ml/kg/min. MET, MAD, and EMG values ranged from 1.0 to 4.9, 0.0020 to 0.4146 g, and 4.3 to 133.9% during lying down and walking at 6 km/h, respectively. Optimal cut-offs to discriminate sedentary activities from non-sedentary activities were 1.3 for METs (sensitivity = 82%, specificity = 88%), 0.0033 g for MAD (sensitivity = 80%, specificity = 91%), and 11.9% for EMG (sensitivity = 79%, specificity = 92%). In conclusion, this study provides applicable thresholds to differentiate sitting and standing and sedentary and non-sedentary activities based on METs, MAD, and EMG in young children.
我们研究了能量消耗、运动感知和肌肉活动在区分儿童久坐和非久坐活动方面的能力。35名7至11岁的儿童参与了这项研究。在包括躺下、坐、站和行走相关活动在内的8种不同的久坐和非久坐活动中，以随机顺序同时进行了摄氧量（V̇O）、三轴加速度计和大腿肌肉肌电图（EMG）的评估。计算了每种活动中连续2分钟时段的V̇O、加速度计和EMG的平均值。在30分钟仰卧休息期间测量静息能量消耗（REE）。计算每种活动的直接测量的任务代谢当量（METs，活动中的V̇O/REE中的V̇O）。计算加速度计的平均幅度偏差（MAD）。对EMG进行标准化，以适应自定步速行走期间的平均肌肉活动。通过受试者工作特征曲线和基于最大敏感性和特异性的最佳临界值，研究了METs、MAD和EMG区分久坐活动和体力活动的分类准确性。平均（标准差）REE为5.0±0.8毫升/千克/分钟。在躺下和以6公里/小时行走时，MET、MAD和EMG值分别为1.0至4.9、0.0020至0.4146克和4.3至133.9%。区分久坐活动和非久坐活动的最佳临界值为：METs为1.3（敏感性=82%，特异性=88%），MAD为0.0033克（敏感性=80%，特异性=91%），EMG为11.9%（敏感性=79%，特异性=92%）。总之，本研究提供了基于METs、MAD和EMG区分幼儿坐立以及久坐和非久坐活动的适用阈值。
