title: Changes in muscle thickness after exercise and biofeedback in people with low back pain.
abstract: BACKGROUND
  Individuals with low back pain (LBP) have reduced function of the transversus abdominis (TrA) and lumbar multifidus (LM) muscles. Biofeedback during exercise may increase the ability to contract the TrA and LM muscles compared with exercise alone.
  
  
  OBJECTIVE
  To compare TrA preferential activation ratio (PAR) and the percent change in LM-muscle thickness in patients with LBP history before and after exercise with or without biofeedback.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  20 LBP individuals, 10 exercise alone and 10 exercise with biofeedback.
  
  
  METHODS
  Patients were allotted to tabletop exercises in isolation or tabletop exercises with visual, auditory, and tactile biofeedback.
  
  
  METHODS
  TrA PAR and percent change in LM-muscle thickness.
  
  
  RESULTS
  There were no differences between groups at baseline (all P > .05). Nonparametric statistics showed decreased resting muscle thickness for total lateral abdominal-wall muscles (P = .007) but not TrA (P = .410) or LM (P = .173). Percent TrA thickness increased from table to standing positions before (P = .006) and after exercise (P = .009). TrA PAR increased after exercise (pre 0.01 ± 0.02, post 0.03 ± 0.04, P = .033) for all patients and for exercise with biofeedback (pre 0.02 ± 0.01, post 0.03 ± 0.01, P = .037) but not for exercise alone (pre 0.01 ± 0.02, post 0.02 ± 0.05, P = .241). No group differences were observed for TrA PAR before (exercise 0.01 ± 0.02, exercise with biofeedback 0.02 ± 0.01, P = .290) or after exercise (exercise 0.02 ± 0.05, exercise with biofeedback 0.03 ± 0.01, P = .174). There were no group differences in LM percent change before exercise (P = .999) or after exercise (P = .597). In addition, no changes were observed in LM percent change as a result of exercise among all participants (P = .391) or for each group (exercise P = .508, exercise with biofeedback P = .575).
  
  
  CONCLUSIONS
  TrA PAR increased after a single session of exercises, whereas no thickness changes occurred in LM.
authors.affiliation: Fairfax County Public School Athletic Training Education Program, McLean High School, McLean Virginia.
authors.forename: Shandi L
authors.initials: SL
authors.lastname: Partner
authors.forename: Mark Alan
authors.initials: MA
authors.lastname: Sutherlin
authors.forename: Shellie
authors.initials: S
authors.lastname: Acocello
authors.forename: Susan A
authors.initials: SA
authors.lastname: Saliba
authors.forename: Eric M
authors.initials: EM
authors.lastname: Magrum
authors.forename: Joe M
authors.initials: JM
authors.lastname: Hart
mesh_terms: D000009:Abdominal Muscles / Q000033:anatomy & histology* / Q000502:physiology; D000328:Adult; D001676:Biofeedback, Psychology; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D055815:Young Adult