title: Is muscle co-activation a predisposing factor for low back pain development during standing? A multifactorial approach for early identification of at-risk individuals.
abstract: OBJECTIVE
  Low back pain development has been associated with static standing postures in occupational settings. Previous work has demonstrated gluteus muscle co-activation as a predominant pattern in previously asymptomatic individuals who develop low back pain when exposed to 2-h of standing. The purpose of this work was to investigate muscle co-activation as a predisposing factor in low back pain development while including a multifactorial approach of clinical assessment tools and psychosocial assessments to identify individuals who are at risk for pain development during standing.
  
  
  RESULTS
  Forty percent of participants developed low back pain during the 2-h of standing. Pain developers demonstrated bilateral gluteus medius and trunk flexor-extensor muscle co-activation prior to reports of pain development. Pain developers and non-pain developers demonstrated markedly different patterns of muscle activation during the 2-h of standing. A novel screening test of active hip abduction was the only clinical assessment tool that predicted pain development.
  
  
  CONCLUSIONS
  Gluteus medius and trunk muscle co-activation appears to be a predisposing rather than adaptive factor in low back pain development during standing. A combination of a positive active hip abduction test and presence of muscle co-activation during standing may be useful for early identification of at-risk individuals.
authors.affiliation: University of Waterloo, Department of Kinesiology, Waterloo, ON, Canada.
authors.forename: Erika
authors.initials: E
authors.lastname: Nelson-Wong
authors.forename: Jack P
authors.initials: JP
authors.lastname: Callaghan
mesh_terms: D000328:Adult; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D004576:Electromyography / Q000379:methods*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000503:physiopathology*; D004856:Postural Balance; D011187:Posture; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis; D055815:Young Adult