Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task
Abstract Background Musculoskeletal disorders are more prevalent among women than among men, which may be explained by aspects of motor control, including neuromuscular requirements and motor variability. Using an exploratory approach, this study aimed to evaluate sex differences in neuromuscular re...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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BMC
2020-01-01
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| Series: | Biology of Sex Differences |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13293-020-0282-2 |
| _version_ | 1831804994630713344 |
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| author | Tessy Luger Robert Seibt Monika A. Rieger Benjamin Steinhilber |
| author_facet | Tessy Luger Robert Seibt Monika A. Rieger Benjamin Steinhilber |
| author_sort | Tessy Luger |
| collection | DOAJ |
| description | Abstract Background Musculoskeletal disorders are more prevalent among women than among men, which may be explained by aspects of motor control, including neuromuscular requirements and motor variability. Using an exploratory approach, this study aimed to evaluate sex differences in neuromuscular responses and motor variability during a repetitive task performed on 3 days. Methods Thirty women and 27 men performed the non-fatiguing, repetitive, 1-h screwing task. For neuromuscular responses, the mean and difference values of static, median, and peak percentile muscle activity levels (normalized to a reference voluntary contraction force) and, for motor variability, the mean and difference values of relative and absolute cycle-to-cycle variability across days were compared between both sexes for each muscle. A mixed-design analysis of variance was used to assess differences between both sexes. Results The non-fatiguing character of the screwing task was confirmed by the absence of decreased force levels in maximal voluntary contractions performed before and after the task and by absence of electromyographic signs of muscle fatigue. The static and median muscle activity levels tended to be higher among women (on average 7.86 and 27.23 %RVE) than men (on average 6.04 and 26.66 %RVE). Relative motor variability of the flexor and biceps muscles and absolute motor variability of both upper arm muscles were lower in women (on average 0.79 and 29.70 %RVE) than in men (on average 0.89 and 37.55 %RVE). The median activity level of both upper arms muscles tended to decrease within days among women (on average - 2.63 %RVE) but increase among men (on average + 1.19 %RVE). Absolute motor variability decreased within days among women (on average - 5.32 to - 0.34%RVE), whereas it tended to decrease less or increase within days among men (on average - 1.21 to + 0.25 %RVE). Conclusion Women showed higher levels of muscle activity and lower initial relative and absolute motor variability than males when performing the same occupational task, implying women may have a higher risk for developing disorders and point to both sexes using different intrinsic motor control strategies in task performance. Clearly, biological aspects alone cannot explain why women would be at higher risk for developing disorders than men. Therefore, a wider range of individual and environmental factors should be taken into account for optimizing work station designs and organizations by taking into account sex differences. |
| first_indexed | 2024-12-22T19:16:11Z |
| format | Article |
| id | doaj.art-0b4441d20d4841acac189088be7608b5 |
| institution | Directory Open Access Journal |
| issn | 2042-6410 |
| language | English |
| last_indexed | 2024-12-22T19:16:11Z |
| publishDate | 2020-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Biology of Sex Differences |
| spelling | doaj.art-0b4441d20d4841acac189088be7608b52022-12-21T18:15:30ZengBMCBiology of Sex Differences2042-64102020-01-0111112410.1186/s13293-020-0282-2Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing taskTessy Luger0Robert Seibt1Monika A. Rieger2Benjamin Steinhilber3Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, University of TübingenInstitute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, University of TübingenInstitute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, University of TübingenInstitute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, University of TübingenAbstract Background Musculoskeletal disorders are more prevalent among women than among men, which may be explained by aspects of motor control, including neuromuscular requirements and motor variability. Using an exploratory approach, this study aimed to evaluate sex differences in neuromuscular responses and motor variability during a repetitive task performed on 3 days. Methods Thirty women and 27 men performed the non-fatiguing, repetitive, 1-h screwing task. For neuromuscular responses, the mean and difference values of static, median, and peak percentile muscle activity levels (normalized to a reference voluntary contraction force) and, for motor variability, the mean and difference values of relative and absolute cycle-to-cycle variability across days were compared between both sexes for each muscle. A mixed-design analysis of variance was used to assess differences between both sexes. Results The non-fatiguing character of the screwing task was confirmed by the absence of decreased force levels in maximal voluntary contractions performed before and after the task and by absence of electromyographic signs of muscle fatigue. The static and median muscle activity levels tended to be higher among women (on average 7.86 and 27.23 %RVE) than men (on average 6.04 and 26.66 %RVE). Relative motor variability of the flexor and biceps muscles and absolute motor variability of both upper arm muscles were lower in women (on average 0.79 and 29.70 %RVE) than in men (on average 0.89 and 37.55 %RVE). The median activity level of both upper arms muscles tended to decrease within days among women (on average - 2.63 %RVE) but increase among men (on average + 1.19 %RVE). Absolute motor variability decreased within days among women (on average - 5.32 to - 0.34%RVE), whereas it tended to decrease less or increase within days among men (on average - 1.21 to + 0.25 %RVE). Conclusion Women showed higher levels of muscle activity and lower initial relative and absolute motor variability than males when performing the same occupational task, implying women may have a higher risk for developing disorders and point to both sexes using different intrinsic motor control strategies in task performance. Clearly, biological aspects alone cannot explain why women would be at higher risk for developing disorders than men. Therefore, a wider range of individual and environmental factors should be taken into account for optimizing work station designs and organizations by taking into account sex differences.https://doi.org/10.1186/s13293-020-0282-2Manual material handlingElectromyographyMotor learningMotor controlMotor variabilitySex differences |
| spellingShingle | Tessy Luger Robert Seibt Monika A. Rieger Benjamin Steinhilber Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task Biology of Sex Differences Manual material handling Electromyography Motor learning Motor control Motor variability Sex differences |
| title | Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task |
| title_full | Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task |
| title_fullStr | Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task |
| title_full_unstemmed | Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task |
| title_short | Sex differences in muscle activity and motor variability in response to a non-fatiguing repetitive screwing task |
| title_sort | sex differences in muscle activity and motor variability in response to a non fatiguing repetitive screwing task |
| topic | Manual material handling Electromyography Motor learning Motor control Motor variability Sex differences |
| url | https://doi.org/10.1186/s13293-020-0282-2 |
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