title: Associations between Trunk Extension Endurance and Isolated Lumbar Extension Strength in Both Asymptomatic Participants and Those with Chronic Low Back Pain.
abstract: BACKGROUND
  Strength and endurance tests are important for both clinical practice and research due to the key role they play in musculoskeletal function. In particular, deconditioning of the lumbar extensor musculature has been associated with low back pain (LBP). Due to the relationship between strength and absolute endurance, it is possible that trunk extension (TEX) endurance tests could provide a proxy measure of isolated lumbar extension (ILEX) strength and thus represent a simple, practical alternative to ILEX measurements. Though, the comparability of TEX endurance and ILEX strength is presently unclear and so the aim of the present study was to examine this relationship.
  
  
  METHODS
  Thirty eight healthy participants and nineteen participants with non-specific chronic LBP and no previous lumbar surgery participated in this cross-sectional study design. TEX endurance was measured using the Biering-Sorensen test. A maximal ILEX strength test was performed on the MedX lumbar-extension machine.
  
  
  RESULTS
  A Pearson's correlation revealed no relationship between TEX endurance and ILEX strength in the combined group (r = 0.035, p = 0.793), the chronic LBP group (r = 0.120, p = 0.623) or the asymptomatic group (r = -0.060, p = 0.720).
  
  
  CONCLUSIONS
  The results suggest that TEX is not a good indicator of ILEX and cannot be used to infer results regarding ILEX strength. However, a combination of TEX and ILEX interpreted together likely offers the greatest and most comprehensive information regarding lumbo-pelvic function during extension.
authors.affiliation: School of Sport, Health and Social Sciences, Southampton Solent University, East Park Terrace, Southampton SO14 0YN, UK. 0conwr69@solent.ac.uk.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Conway
authors.affiliation: School of Sport, Health and Social Sciences, Southampton Solent University, East Park Terrace, Southampton SO14 0YN, UK. 0behej96@solent.ac.uk.
authors.forename: Jessica
authors.initials: J
authors.lastname: Behennah
authors.affiliation: School of Sport, Health and Social Sciences, Southampton Solent University, East Park Terrace, Southampton SO14 0YN, UK. james.fisher@solent.ac.uk.
authors.forename: James
authors.initials: J
authors.lastname: Fisher
authors.affiliation: AECC Clinic, Anglo European College of Chiropractic, Bournemouth BH5 2DF, UK. NOsborne@aecc.ac.uk.
authors.forename: Neil
authors.initials: N
authors.lastname: Osborne
authors.affiliation: School of Sport, Health and Social Sciences, Southampton Solent University, East Park Terrace, Southampton SO14 0YN, UK. james.steele@solent.ac.uk.
authors.forename: James
authors.initials: J
authors.lastname: Steele
keywords: endurance; isolated lumbar extension; low back pain; strength; trunk extension