title: Comparison of lumbo-pelvic kinematics during trunk forward bending and backward return between patients with acute low back pain and asymptomatic controls.
abstract: BACKGROUND
  Prior studies have reported differences in lumbo-pelvic kinematics during a trunk forward bending and backward return task between individuals with and without chronic low back pain; yet, the literature on lumbo-pelvic kinematics of patients with acute low back pain is scant. Therefore, the purpose of this study was set to investigate lumbo-pelvic kinematics in this cohort.
  
  
  METHODS
  A case-control study was conducted to investigate the differences in pelvic and thoracic rotation along with lumbar flexion as well as their first and second time derivatives between females with and without acute low back pain. Participants in each group completed one experimental session wherein they performed trunk forward bending and backward return at self-selected and fast paces.
  
  
  RESULTS
  Compared to controls, individuals with acute low back pain had larger pelvic range of rotations and smaller lumbar range of flexions. Patients with acute low back pain also adopted a slower pace compared to asymptomatic controls which was reflected in smaller maximum values for angular velocity, deceleration and acceleration of lumbar flexion. Irrespective of participant group, smaller pelvic range of rotation and larger lumbar range of flexion were observed in younger vs. older participants.
  
  
  CONCLUSIONS
  Reduced lumbar range of flexion and slower task pace, observed in patients with acute low back pain, may be the result of a neuromuscular adaptation to reduce the forces and deformation in the lower back tissues and avoid pain aggravation.
authors.affiliation: F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY 40506, USA.
authors.forename: Iman
authors.initials: I
authors.lastname: Shojaei
authors.affiliation: College of Nursing, University of Kentucky, Lexington, KY 40506, USA.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Salt
authors.affiliation: Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA.
authors.forename: Quenten
authors.initials: Q
authors.lastname: Hooker
authors.affiliation: Program in Physical Therapy, Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO 63108, USA.
authors.forename: Linda R
authors.initials: LR
authors.lastname: Van Dillen
authors.affiliation: F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY 40506, USA. Electronic address: babak.bazrgari@uky.edu.
authors.forename: Babak
authors.initials: B
authors.lastname: Bazrgari
mesh_terms: D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000502:physiology*; D011187:Posture / Q000502:physiology; D012399:Rotation; D060726:Torso / Q000502:physiology
keywords: Acute low back pain; Age and motion pace effects; Forward bending and backward return; Lumbo-pelvic kinematics