title: Ultrasound measurement of deep and superficial abdominal muscles thickness during standing postural tasks in participants with and without chronic low back pain.
abstract: BACKGROUND
  Activity of deep abdominal muscles increases the lumbar stability. Majority of previous studies indicated abdominal muscle activity dysfunction during static activity in patients with low back pain (LBP). However, the number of studies that evaluated deep abdominal muscle activity in dynamic standing activities in patients is limited, while this assessment provides better understanding of pain behavior during these activities.
  
  
  OBJECTIVE
  Investigation of superficial and deep abdominal muscles activity in participants with chronic LBP as compared to healthy individuals during standing tasks.
  
  
  METHODS
  Case control study.
  
  
  METHODS
  Ultrasound imaging was used to measure the thickness of transverse abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles in female participants with (N = 45) and without chronic LBP (CLBP) (N = 45) during tests. The Biodex Balance System was used to provide standing tasks. The thickness of each muscle in a standing task was normalized to actual thickness at rest in the supine lying position to estimate its activity.
  
  
  RESULTS
  The results indicate increases in thickness of all muscles in both groups during dynamic as compared to static standing tasks (P < 0.05, ES > 0.5). Lower percentages of thickness change for TrA muscle and higher for EO muscle were found in the patients as compared to healthy individuals during all tests (P < 0.05, ES > 1.28).
  
  
  CONCLUSIONS
  Higher activity of superficial than deep abdominal muscles in patients as compared to healthy individuals during standing tasks indicates motor control dysfunction in patients with CLBP. Standing tasks can discriminate the individuals with and without LBP and can be progressively used in training.
authors: Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran; Neuromuscular Rehabilitation Research Center, Semnan University of Medical Sciences, Semnan, Iran.
authors: Fatemeh
authors: F
authors: Ehsani
authors: Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Electronic address: arabloo_masoud@hotmail.com.
authors: Amir Massoud
authors: AM
authors: Arab
authors: Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
authors: Shapour
authors: S
authors: Jaberzadeh
authors: Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors: Mahyar
authors: M
authors: Salavati
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D014463:Ultrasonography
keywords: Abdominal muscle thickness; Low back pain; Standing postural task; Ultrasound