title: Muscle Activity of Abdominal and Back Muscles during Six Starting Positions in Untrained Individuals.
abstract: OBJECTIVE
  This study aimed to investigate the electromyography (EMG) activity amongfive abdominal and back muscles at six starting positions in untrained individuals.
  
  
  METHODS
  Twenty-five healthy individuals aged 20.9 +/- 3.9 years, who were inexperienced with lumbar stabilization exercise, were recruited. They were asked to perform maximum voluntary isometric contraction (MVIC), and then six starting positions in random order EMG data ofeach starting position were normalized as a percentage of MVIC. Friedman two-way analysis of variance (ANOVA) and Wilcoxon signed-ranks tests were used for data analysis.
  
  
  RESULTS
  Significant differences in EMG activity of five abdominal and back muscles were found in all six starting positions (p<0.001). The highest EMG activity ofthe transversus abdominis/internal abdominal oblique (TrA/IO) was found in crook lying, with right leg lifted (CLR), and of multifidus (MF) in four-point kneeling with straight right leg lifted horizontally (4p-SRL).
  
  
  CONCLUSIONS
  The results suggested that CLR and sitting on a gym ball (SG) were able tofacilitate TrA/IO activity with minimal activity from the rectus abdominis (RA), while CL, 4p-SRL, andSG were able tofacilitate MF activity with minimal activity from erector spinae (ES).
authors.forename: Prasert
authors.initials: P
authors.lastname: Sakulsriprasert
authors.forename: Penpailin
authors.initials: P
authors.lastname: Eak-udchariya
authors.forename: Wattana
authors.initials: W
authors.lastname: Jalayondeja
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology*; D000704:Analysis of Variance; D064131:Back Muscles / Q000502:physiology*; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008161:Lumbosacral Region; D008297:Male; D011187:Posture / Q000502:physiology*; D055815:Young Adult