title: Prediction of maximal back muscle strength from indices of body mass and fat-free body mass.
abstract: OBJECTIVE
  The purpose of this study was to examine, in healthy volunteers, the relationship between back extensor muscle strength and body size.
  
  
  METHODS
  The maximal voluntary isometric back extensor strength of 456 volunteers, aged 18-42 yr and with no history of low back pain, was measured in a standing, slightly flexed forward posture. This was then correlated with two indices of body size: body mass and fat-free body mass.
  
  
  RESULTS
  Significant linear relationships were observed between back muscle strength and each of the two indices of body size. There was a gender difference in both the slope and the intercept of the regression equations describing the relationships. There was no independent influence of age within the range studied.
  
  
  CONCLUSIONS
  It was possible to establish predictive equations for back extensor strength based on body size which could be used to quantify strength 'deficits', for instance in patients with low back pain, and to prescribe submaximal target forces for use in endurance training and testing.
authors.affiliation: Department of Anatomy, University of Bristol, UK.
authors.forename: A F
authors.initials: AF
authors.lastname: Mannion
authors.forename: M A
authors.initials: MA
authors.lastname: Adams
authors.forename: R G
authors.initials: RG
authors.lastname: Cooper
authors.forename: P
authors.initials: P
authors.lastname: Dolan
mesh_terms: D000328:Adult; D001824:Body Constitution; D005260:Female; D006801:Humans; D017116:Low Back Pain; D008161:Lumbosacral Region; D008297:Male; D015233:Models, Statistical; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance; D011237:Predictive Value of Tests; D016474:Weight-Bearing