title: Observation of Age-Related Decline in the Performance of the Transverse Abdominis Muscle.
abstract: BACKGROUND
  Previous research has shown that the performance of skeletal muscle declines with advancing age. Coordination of the transverse abdominis (TrA), a deep postural muscle, has been shown to be reduced in persons with low back pain. No previous research has studied the effect of age on the activation on this muscle.
  
  
  OBJECTIVE
  To assess the effect of age on TrA activation in response to rapid arm abduction.
  
  
  METHODS
  Cross-sectional cohort study.
  
  
  METHODS
  University exercise physiology laboratory.
  
  
  METHODS
  A total of 18 adult men (aged 27 ± 7.0 years) for the younger group and 11 older adults (5 men and 6 women, aged 59.6 ± 4.0 years) were recruited for this study.
  
  
  METHODS
  Participants were positioned on a treatment table and performed a series of rapid arm abduction movements with their right arm while the activation of the TrA muscle was recorded using ultrasound imaging. Onset of arm abduction was measured using surface electromyography and synchronized with the ultrasound through the ultrasound unit's electrocardiogram channel. The mean time difference between the 2 events was calculated during post-hoc analysis.
  
  
  METHODS
  A Mann-Whitney test was performed to test for differences in the onset performance of the TrA muscle between the 2 groups.
  
  
  RESULTS
  Results showed that the older group was significantly slower than the younger group in engaging their TrA in response to the rapid arm abduction (P = .036). A separate analysis of the older group data showed that no significant differences existed between the male and female participants that could potentially have acted as a confounding factor for the main finding (P = .126).
  
  
  CONCLUSIONS
  This study shows that older adults were slower than younger adults in activating their TrA muscle in response to rapid arm abduction. This delay has the potential to lead to increased occasions when the low back is unprotected, increasing the likelihood of injury or low back pain.
authors.affiliation: University of Wolverhampton, Institute of Sport, Gorway Road, Walsall, West Midlands WS1 3BD, United Kingdom(∗). Electronic address: paul.davies@wlv.ac.uk.
authors.forename: Paul
authors.initials: P
authors.lastname: Davies
authors.affiliation: Institute of Clinical Exercise and Health Science, University of the West of Scotland, Hamilton, Scotland(†).
authors.forename: Fergal M
authors.initials: FM
authors.lastname: Grace
authors.affiliation: National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Science, Loughborough University, Loughborough, UK(‡).
authors.forename: Mark P
authors.initials: MP
authors.lastname: Lewis
authors.affiliation: Institute of Clinical Exercise and Health Science, University of the West of Scotland, Hamilton, Scotland(¶).
authors.forename: Nicholas
authors.initials: N
authors.lastname: Sculthorpe
mesh_terms: D000009:Abdominal Muscles / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D055948:Sarcopenia / Q000503:physiopathology*