EMG trapezius muscle activity pattern in string players: Part II-Influences of basic body awareness therapy on the violin playing technique [An ... Journal of Industrial Ergonomics]

EMG trapezius muscle activity pattern in string players: Part II-Influences of basic body awareness therapy on the violin playing technique [An ... Journal of Industrial Ergonomics] Review

This digital document is a journal article from International Journal of Industrial Ergonomics, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
This study used electromyography (EMG) to investigate if violinists could play with a greater variation in the trapezius muscle activity pattern after an 8-week training program with Basic Body Awareness Therapy (Basic BAT), as compared with a reference group. Five professional orchestra violinists who trained Basic BAT were compared to nine violinists working as violin teachers or music students at higher education level who did not take part in any training. The trapezius muscle activity, while playing a piece of music, was monitored by bilateral surface EMG before and after the 8-week training period. Exposure Variation Analysis (EVA) and Principal Component Analysis (PCA) were used for the EMG analyses. No significant differences were found in the trapezius muscle activation between the Basic BAT-trained group and the reference group. The training group perceived positive changes in breathing, muscular tension, postural control and concentration mainly during practice sessions. Musicians might benefit from practicing warming up, taking regular pauses to recover and proper working technique in activities other than playing an instrument. Relevance to industry: Proper work technique, work postures and movements are important to prevent neck and shoulder problems. This study shows a pedagogical approach to modify posture and bodily reactions during work tasks.

EMG trapezius muscle activity pattern in string players: Part II-Influences of basic body awareness therapy on the violin playing technique [An article ... Journal of Industrial Ergonomics]

EMG trapezius muscle activity pattern in string players: Part II-Influences of basic body awareness therapy on the violin playing technique [An article ... Journal of Industrial Ergonomics] Review

This digital document is a journal article from International Journal of Industrial Ergonomics, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
This study used electromyography (EMG) to investigate if violinists could play with a greater variation in the trapezius muscle activity pattern after an 8-week training program with Basic Body Awareness Therapy (Basic BAT), as compared with a reference group. Five professional orchestra violinists who trained Basic BAT were compared to nine violinists working as violin teachers or music students at higher education level who did not take part in any training. The trapezius muscle activity, while playing a piece of music, was monitored by bilateral surface EMG before and after the 8-week training period. Exposure Variation Analysis (EVA) and Principal Component Analysis (PCA) were used for the EMG analyses. No significant differences were found in the trapezius muscle activation between the Basic BAT-trained group and the reference group. The training group perceived positive changes in breathing, muscular tension, postural control and concentration mainly during practice sessions. Musicians might benefit from practicing warming up, taking regular pauses to recover and proper working technique in activities other than playing an instrument. Relevance to industry: Proper work technique, work postures and movements are important to prevent neck and shoulder problems. This study shows a pedagogical approach to modify posture and bodily reactions during work tasks.

Mechanical load and EMG activity in the neck induced by different head-worn equipment and neck postures [An article from: International Journal of Industrial Ergonomics]

Mechanical load and EMG activity in the neck induced by different head-worn equipment and neck postures [An article from: International Journal of Industrial Ergonomics] Review

This digital document is a journal article from International Journal of Industrial Ergonomics, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Background: When working in darkness, helicopter pilots often use night vision goggles (NVG) and a counterweight (CW) attached to the helmet. In addition, missions also entail whole-body vibration and ergonomically unfavorable neck and body postures. The present aim was to assess the mechanical load and compare it with previously published data comprising recordings of muscle activity induced by different head-worn equipment used by helicopter pilots. Methods: Activity in left upper and lower dorsal neck muscles was recorded in 14 Swedish helicopter pilots, using electromyography (EMG) when wearing (i) helmet, (ii) helmet and NVG, and (iii) helmet, NVG and CW in a laboratory setting. The activity was recorded in a random order with the head in neutral position and at 20^o neck flexion. The induced load for the cervical spine in these conditions was calculated using a sagittal, static, biomechanical model. Results: The induced flexing load moment and muscle activity increased with the NVG and decreased from that level with the CW. However, the magnitude of the induced load was higher than the muscle activity indicated, especially when related to maximum strength. Conclusion: At low loads, as apparent in the present study, substantial increases in induced load moment are entailed, with only a comparatively small increase in neck-muscle activation levels. This must be considered when using EMG in the assessment of work load and in ergonomic interventions. Relevance to industry: As EMG is a common method of assessing excessive muscle activity as a sign of workload exposure, it is essential to note the non-linear relation between the neck-muscle activity and the induced flexing load moment caused by head-worn equipment.

EMG trapezius muscle activity pattern in string players: [An article from: International Journal of Industrial Ergonomics]

EMG trapezius muscle activity pattern in string players: [An article from: International Journal of Industrial Ergonomics] Review

This digital document is a journal article from International Journal of Industrial Ergonomics, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Work related neck and shoulder disorders are a great problem for string musicians. A playing technique with more relaxed muscles and a greater variation in the muscle activity pattern, i.e., with shorter sequences at a varied number of amplitude levels as reflected by electromyography (EMG), might prevent pain. This study used EMG to study variations in the trapezius muscle activity pattern in 12 string musicians performing a piece of music at two playing sessions separated by a ten-week interval. Nine of the string musicians played violin, two viola and one cello. Exposure variation analysis and principal component analysis were used for analysis of the EMG. The trapezius muscle activity pattern was similar in the first and second playing sessions showing that each musician repeated his/her own muscular activity pattern. However, there was considerable variability in the muscle activity pattern between cello, violin and viola players and between individual violin players. Thus, this EMG method has the potential to identify variations and reproducibility of trapezius muscle activity in string musicians. This method may be used to analyse individual differences when performing a musical work task and to evaluate intervention studies. Relevance to industry: Intervention studies on muscle activity pattern which try to change the work technique need to be evaluated.

Velocity-dependent EMG activity of masseter and sternocleidomastoideus muscles during a ballistic arm thrusting movement [An article from: Human Movement Science]

Velocity-dependent EMG activity of masseter and sternocleidomastoideus muscles during a ballistic arm thrusting movement [An article from: Human Movement Science] Review

This digital document is a journal article from Human Movement Science, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Two experiments were conducted to investigate the functional relationship between the general somatic motor function and the oral motor function. In Experiment 1, we analyzed the relationship between the amount of masseter muscle (MSS) activity and the velocity of a ballistic, 'karate-do' arm thrusting movement (ThrMov). ThrMov velocity was measured from video images taken with a high-speed CCD camera at a frequency of 500Hz. EMGs of MSS and sternocleidomastoideus (SCM) muscles as well as other related muscles were recorded simultaneously with video images in 6 varsity 'karate-do' athletes. Pearson's correlation coefficients were calculated between EMG amplitude and movement velocity. EMG activity of MSS as well as the other muscles increased as a function of ThrMov velocity in all participants, as evidenced by highly significant (p<.01) correlation coefficients, ranging from .64 to .87 (mean: .75). MSS EMG activity attained during ThrMovs performed at maximum velocity ranged between 14.6% and 113.8% of this muscle's MVC (45.7+/-39.3% MVC, mean+/-SD). SCM was also strongly active and closely associated with MSS. Besides changes in amount of EMG activity, it was further found that R-MSS EMG onset progressively shifted to the earlier phase of the ThrMov as ThrMov velocity increased. EMG onset time of R-MSS as well as R- and L-SCMs was negatively correlated with ThrMov velocity; when performed at maximum velocity MSS activation preceded the start of ThrMov by more than 100ms, whereas MSS was recruited last at ~150ms after the start of ThrMov when performed at moderate speed (~50% of maximum). In Experiment 2, the effects of head movement relative to the trunk on R-MSS and SCMs EMG activity were tested in both gazing and sidelong glancing conditions. A much smaller head rotation relative to the trunk was necessary during the ThrMov in the sidelong glancing condition compared to the gazing condition. R-MSS EMG activity was affected significantly by the difference between these conditions and decreased by 5.2% MVC in the sidelong glancing condition compared to the gazing condition. In association with the change in requirement for head movement between those conditions, EMG balance between the bilateral SCMs changed substantially. Finally, marked muscle activity during ThrMov was found in the MSS that was not directly involved in performing this movement, indicating a form of 'remote facilitation'.