Comparison of indices used for quantifying the total EMG of shoulder muscles

Alternative Title
Alternative Author(s)
일반대학원 산업공학과
The Graduate School, Ajou University
Publication Year
One-handed handlingElectromyographyTotal muscular strainTotal EMG index
Alternative Abstract
Electromyography (EMG) is used to measure the electrical activity of specific muscles in assessment of physical workload. Generally, the activity levels of muscles were presented individually; however, in order to provide a global indicator of stress and strain of workload, it need to use a kind of index to account the "total" muscular load of overall muscles. This study implied three typical indices: (1) summation EMG index, (3) magnitude EMG index and (3) weighted EMG index in the evaluation of total muscular effort of shoulder. Ten male participants were asked perform one-handed handling tasks under 162 experimental conditions. EMG of ten superficial shoulder muscles were collected and combined by three indices. Heart rate and oxygen uptake were measured simultaneously. The relationship between EMG activity and physiological response was studied, and the effects of EMG index, physiological response, direction (upward, downward, rightward, leftward, forward, backward), weight (1, 4, and 7 kg), frequency (2, 6, and 10 cycle/min), as well as distance (20, 40, and 60 cm) on correlation coefficient were analyzed. The results showed that weight had effect on correlation coefficient, where heavier weight resulted in higher correlation coefficient. Frequency also could influence correlation coefficient. Larger frequency was associated with greater muscular demand, physiological responses. 3 kinds of total EMG index studied in the present study were able to differentiate various one-handed handling tasks. The weighted EMG index which revealed a little higher correlation coefficient is recommended. The results of this study was able to provide a method to compare the sensitivity when quantifying the muscle activity of overall muscles, and to give important recommendations for evaluating total effort of shoulder in manual material handling tasks.

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Special Graduate Schools > Graduate School of Science and Technology > Department of Industrial Engineering > 3. Theses(Master)
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