title: Raised paraspinal muscle activity reduces rate of stature recovery after loaded exercise in individuals with chronic low back pain.
abstract: OBJECTIVE
  To further the understanding of stature recovery in subjects with and without chronic low back pain (CLBP) and to determine the relations among stature recovery, paraspinal muscle activity, and perceived pain and disability.
  
  
  METHODS
  A case-control study in which stature loss and recovery were assessed in subjects with and without CLBP after a 20-minute loaded walking task (10% of body mass). Group differences in pain, disability, and paraspinal muscle activity were also assessed.
  
  
  METHODS
  A university laboratory.
  
  
  METHODS
  Twenty subjects with CLBP were matched (age, sex, body mass, physical activity level) with 20 controls who were recruited through notices in the university, general community, and local Primary Care Trust.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Stature changes and integrated electromyograms of the paraspinal muscles during a loading and unloading period were assessed.
  
  
  RESULTS
  Stature changes after loading did not differ between groups ( P <.05). Subjects with CLBP recovered significantly less stature during unloading than did the controls ( P <.05). Paraspinal muscle activity correlated negatively with stature recovery ( P <.05). Relations among stature recovery, pain, and disability were shown ( P <.05).
  
  
  CONCLUSIONS
  The elevated paraspinal muscle activity exhibited by the CLBP group increased compression on the intervertebral disks and diminished their ability to recover the height lost through loaded exercise. Further research is required to establish whether a change in paraspinal muscle activity is associated with corresponding changes in stature recovery, and if this has any clinical implications by reducing pain and disability.
authors.affiliation: Department of Exercise and Sport Science, Manchester Metropolitan University, Stoke-on-Trent, UK. e.l.healey@mmu.ac.uk
authors.forename: Emma L
authors.initials: EL
authors.lastname: Healey
authors.forename: Neil E
authors.initials: NE
authors.lastname: Fowler
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Burden
authors.forename: Islay M
authors.initials: IM
authors.lastname: McEwan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D006233:Persons with Disabilities / Q000534:rehabilitation*; D004576:Electromyography; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*