Research Goal
After analyzing the muscle activity level and fatigue level when 6-10 year old children play a scale model (using the EMG analysis tool), the muscle activity level and fatigue level when playing the traditional Korean instrument were compared.
UX Research with Physiology methods
Equipments
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EMG: measuring muscle activity and fatigue
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SPM: waist bending information, acceleration measurement
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Borg Scale: Surveying the level of stress.
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Anthropometry
Anthropometry
EMG Device
Muscle parts for EMG measuring
Method of data analysis
Data is analyzed by RMS (Root mean square) method to know muscle usage, and MPF (Mean Power Frequency) analysis is used for fatigue level MPF compares before and after fatigue by using frequency shift from high frequency to low frequency when fatigue occurs.
SEMG power spectrum density - before (a) and after (b) fatiguing exercise (De Luca, 1984)
Procedures
It can be seen that when the muscle is tired, the frequency value of the EMG decreases. Based on this basis, it is possible to quantitatively grasp muscle fatigue according to the amount of change in the frequency value of the muscle during repeated playing.
Results
Among the three musical instruments, the results for verifying the physical load of Gayageum can be listed as follows. Looking at the RMS value, which measures the muscle activity of the children's participants when they played the adult gayageum and the reduced model, and the MPF value, the fatigue value that appears during repeated playing, most of the reduced models showed less activity and less fatigue than the adult gayageum.
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When in the gayageum playing position, the shoulder muscles use more of the shoulder and lower back
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The right shoulder has reduced muscle use in the existing gayageum playing posture. It can be seen that the muscle use is more than the gayageum.
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It is judged that the reason why the left shoulder (lower left neck) uses a lot of muscle is that both shoulders divide the load evenly as the size of the gayageum is reduced to the large load on the right shoulder when playing gayageum.
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The lower back is reduced in both the right and left muscles. When the gayageum playing position is used, the muscle use is reduced compared to the existing gayageum playing position
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In order to remove outliers and disturbances of the signal, the area with the most stable signal is selected for 3-6 seconds and converted into MPF (Mean Power Frequency) value for analysis
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The higher the fatigue level, the higher and lower the fatigue level is compared by the difference in the value (transition value) that the muscle signal moves from high frequency to low frequency.
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Physiologically verifying whether the fatigue level is relatively reduced when children are repeatedly held for 30 seconds after taking the playing position of the existing gayageum and reduced gayageum, and the existing and reduced gayageum.
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Gayageum's overall fatigue was lower than that of conventional instruments in scaled instruments.