title: Back pain is associated with changes in loading pattern throughout forward and backward bending.
abstract: METHODS
  Experimental study to determine the kinetics of the lumbar spine (LS) and hips during forward and backward bending.
  
  
  OBJECTIVE
  To investigate the effects of back pain, with and without a positive straight leg raise (SLR) sign, on the loading patterns in the LS and hip during forward and backward bending.
  
  
  BACKGROUND
  Forward and backward bending are important components of many functional activities and are part of routine clinical examination. However, there is a little information about the loading patterns during forward and backward bending in people with back pain with or without a positive SLR sign.
  
  
  METHODS
  Twenty asymptomatic participants, 20 back pain participants, and 20 participants with back pain and a positive SLR sign performed 3 continuous cycles of forward and backward bending. Electromagnetic sensors were attached to body segments to measure their kinematics while 2 nonconductive force plates gathered ground reaction force data. A biomechanical model was used to determine the loading pattern in LS and hips.
  
  
  RESULTS
  Although the loading on the LS at the end of the range decreased significantly, the loading at the early and middle ranges of forward bending actually increased significantly in people with back pain, especially in those with positive SLR sign. This suggests that resistance to movement is significantly increased in people with back pain during this movement.
  
  
  CONCLUSIONS
  This study suggested that it is not sufficient to study the spine at the end of range only, but a complete description of the loading patterns throughout the range is required. Although the maximum range of motion of the spine is reduced in people with back pain, there is a significant increase in the moment acting through the range, particularly in those with a positive SLR sign.
authors.affiliation: School of Health Professions, University of Plymouth, Plymouth, United Kingdom.
authors.forename: Gary L K
authors.initials: GL
authors.lastname: Shum
authors.forename: Jack
authors.initials: J
authors.lastname: Crosbie
authors.forename: Raymond Y W
authors.initials: RY
authors.lastname: Lee
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001416:Back Pain / Q000503:physiopathology*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*