Mbody EMG data superior over accelerometry in daily activity measurements
Accelerometry has been widely used to measure physical activity. Even if there is research showing inaccuracy of accelerometry, there is not much comparison research with muscle activity (surface electromyography, EMG). University of Jyväskylä has concluded three years program about children’s physical activity. Research highlighted the accuracy of Myontec Mbody shorts to measure physical activity over accelerometry especially in the assessment of low intensity physical activity and in short-lasting sporadic activity bouts.
Studies have been showing earlier that measuring muscle activity using EMG may provide more direct information on sedentary behavior and physical activity than accelerometry (Hamilton et al., 2007; Hamilton, 2017). Furthermore, previous studies have determined EMG thresholds for sedentary activities using Mbody data derived from adults (Tikkanen et al., 2013, 2014; Pesola et al., 2016).
When comparing results in physical activity found that accelerometry counts and EMG amplitude showed marked differences in swinging, trampoline jumping, crawling, static squat, single leg hops, standing long jump and jump for height, the difference being over 170% when signals were normalized to that during walking. Furthermore, in walking, swinging, trampoline jumping, stair negotiation and crawling ACC classified over 60% of the time as vigorous-intensity activity, while EMG indicated primarily light- and moderate-intensity activities.
Proportion of time in sedentary, light, moderate and vigorous activity intensity level in various tasks compared with accelerometry (ACC) and electromyography (EMG). Source Gao et al. 2018.
Duration of light, moderate and vigorous activity varied considerably between the methods especially during walking, stair negotiation, crawling, swinging and trampoline jumping.
Findings were part of the three years research program, CHIPASE - Children’s physical activity spectrum: daily variations in physical activity and sedentary patterns related to school indoor physical environment, made in University of Jyväskylä.
Gao Y, Melin M, Mäkäräinen K, Rantalainen T, Pesola AJ, Laukkanen A, Sääkslahti A, Finni T. (2018) Children’s physical activity and sedentary time compared using assessments of accelerometry counts and muscle activity level. PeerJ 6:e5437.
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