Muscle function and fatigability of trunk flexors in males and females
Abstract Background Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are established for many limb muscles and back extensor muscles, but it is unknown if sex differences exist for the...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2017-04-01
|
| Series: | Biology of Sex Differences |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13293-017-0133-y |
| _version_ | 1819022127048687616 |
|---|---|
| author | Rita E. Deering Jonathon W. Senefeld Tatyana Pashibin Donald A. Neumann Sandra K. Hunter |
| author_facet | Rita E. Deering Jonathon W. Senefeld Tatyana Pashibin Donald A. Neumann Sandra K. Hunter |
| author_sort | Rita E. Deering |
| collection | DOAJ |
| description | Abstract Background Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are established for many limb muscles and back extensor muscles, but it is unknown if sex differences exist for the abdominal muscles despite their functional importance. Methods Eighteen females (24.3 ± 4.8 years) and 15 males (24.1 ± 6.6 years) performed (1) isometric trunk flexion maximal voluntary contractions (MVCs) in a range of trunk positions to establish a torque-angle curve and (2) submaximal (50% MVC), intermittent isometric contraction (6 s on, 4 s off) until task failure to determine fatigability of the trunk flexor muscles. Dual X-ray absorptiometry quantified body fat and lean mass. Physical activity levels were quantified with a questionnaire. Torque-angle curves, electromyography (EMG), MVC torque, and torque steadiness were compared with repeated measures ANOVA with sex as a between-subjects factor. Results For the torque-angle curve, MVC torque was reduced as the trunk angle increased toward flexion (p < 0.001). Males had greater MVC torque than females at the extended positions (31% difference), with no sex differences in torque in upright sitting (p > 0.05). Time-to-task failure for the submaximal fatigability task in upright sitting was similar between males and females (12.4 ± 7 vs 10.5 ± 6 min). Time-to-task failure was positively associated with strength (r = 0.473, p = 0.005) and self-reported physical activity (r = 0.456, p = 0.030). Lean mass in the trunk was positively associated with trunk flexor strength (r = 0.378, p = 0.011) and self-reported physical activity (r = 0.486, p = 0.007). Finally, torque steadiness [coefficient of variation of torque (CV)] during submaximal isometric contractions decreased with contraction intensity and was similar for males and females across all intensities. Conclusions Unlike many limb muscle groups, males and females had similar fatigability and torque steadiness of the trunk flexor muscles during isometric contractions. Stronger individuals, however, exhibited less fatigability. Lower self-reported physical activity was associated with greater fatigability of trunk flexor muscles. The relationship between strength and fatigability of the trunk flexor muscles and physical activity supports the importance of abdominal muscle strengthening to offset fatigability in both males and females. |
| first_indexed | 2024-12-21T04:18:03Z |
| format | Article |
| id | doaj.art-1ab1d6d8184d4f88be4572f8df8ffc6f |
| institution | Directory Open Access Journal |
| issn | 2042-6410 |
| language | English |
| last_indexed | 2024-12-21T04:18:03Z |
| publishDate | 2017-04-01 |
| publisher | BMC |
| record_format | Article |
| series | Biology of Sex Differences |
| spelling | doaj.art-1ab1d6d8184d4f88be4572f8df8ffc6f2022-12-21T19:16:16ZengBMCBiology of Sex Differences2042-64102017-04-018111210.1186/s13293-017-0133-yMuscle function and fatigability of trunk flexors in males and femalesRita E. Deering0Jonathon W. Senefeld1Tatyana Pashibin2Donald A. Neumann3Sandra K. Hunter4Department of Physical Therapy, Marquette UniversityDepartment of Physical Therapy, Marquette UniversityDepartment of Physical Therapy, Marquette UniversityDepartment of Physical Therapy, Marquette UniversityDepartment of Physical Therapy, Marquette UniversityAbstract Background Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are established for many limb muscles and back extensor muscles, but it is unknown if sex differences exist for the abdominal muscles despite their functional importance. Methods Eighteen females (24.3 ± 4.8 years) and 15 males (24.1 ± 6.6 years) performed (1) isometric trunk flexion maximal voluntary contractions (MVCs) in a range of trunk positions to establish a torque-angle curve and (2) submaximal (50% MVC), intermittent isometric contraction (6 s on, 4 s off) until task failure to determine fatigability of the trunk flexor muscles. Dual X-ray absorptiometry quantified body fat and lean mass. Physical activity levels were quantified with a questionnaire. Torque-angle curves, electromyography (EMG), MVC torque, and torque steadiness were compared with repeated measures ANOVA with sex as a between-subjects factor. Results For the torque-angle curve, MVC torque was reduced as the trunk angle increased toward flexion (p < 0.001). Males had greater MVC torque than females at the extended positions (31% difference), with no sex differences in torque in upright sitting (p > 0.05). Time-to-task failure for the submaximal fatigability task in upright sitting was similar between males and females (12.4 ± 7 vs 10.5 ± 6 min). Time-to-task failure was positively associated with strength (r = 0.473, p = 0.005) and self-reported physical activity (r = 0.456, p = 0.030). Lean mass in the trunk was positively associated with trunk flexor strength (r = 0.378, p = 0.011) and self-reported physical activity (r = 0.486, p = 0.007). Finally, torque steadiness [coefficient of variation of torque (CV)] during submaximal isometric contractions decreased with contraction intensity and was similar for males and females across all intensities. Conclusions Unlike many limb muscle groups, males and females had similar fatigability and torque steadiness of the trunk flexor muscles during isometric contractions. Stronger individuals, however, exhibited less fatigability. Lower self-reported physical activity was associated with greater fatigability of trunk flexor muscles. The relationship between strength and fatigability of the trunk flexor muscles and physical activity supports the importance of abdominal muscle strengthening to offset fatigability in both males and females.http://link.springer.com/article/10.1186/s13293-017-0133-yTrunk flexorsSex differencesFatigabilityStrengthAbdominal muscles |
| spellingShingle | Rita E. Deering Jonathon W. Senefeld Tatyana Pashibin Donald A. Neumann Sandra K. Hunter Muscle function and fatigability of trunk flexors in males and females Biology of Sex Differences Trunk flexors Sex differences Fatigability Strength Abdominal muscles |
| title | Muscle function and fatigability of trunk flexors in males and females |
| title_full | Muscle function and fatigability of trunk flexors in males and females |
| title_fullStr | Muscle function and fatigability of trunk flexors in males and females |
| title_full_unstemmed | Muscle function and fatigability of trunk flexors in males and females |
| title_short | Muscle function and fatigability of trunk flexors in males and females |
| title_sort | muscle function and fatigability of trunk flexors in males and females |
| topic | Trunk flexors Sex differences Fatigability Strength Abdominal muscles |
| url | http://link.springer.com/article/10.1186/s13293-017-0133-y |
| work_keys_str_mv | AT ritaedeering musclefunctionandfatigabilityoftrunkflexorsinmalesandfemales AT jonathonwsenefeld musclefunctionandfatigabilityoftrunkflexorsinmalesandfemales AT tatyanapashibin musclefunctionandfatigabilityoftrunkflexorsinmalesandfemales AT donaldaneumann musclefunctionandfatigabilityoftrunkflexorsinmalesandfemales AT sandrakhunter musclefunctionandfatigabilityoftrunkflexorsinmalesandfemales |