title: Chronic low back pain sufferers exhibit freezing-like behaviors when asked to move their trunk as fast as possible.
abstract: BACKGROUND
  The effect of chronic low back pain (CLBP) on the kinematic parameters of trunk motion has received much more interest in this last decade. However, there are no descriptions of the motor strategies that occur when patients perform trunk movements in the three anatomical planes at different pace conditions.
  
  
  OBJECTIVE
  To investigate motor strategies used by CLBP patients and asymptomatic people while performing different go and back trunk movements in an upright standing position.
  
  
  METHODS
  A comparative study.
  
  
  METHODS
  The control group (CG, n=33) included 14 men and 19 women with no history of low back pain, and the chronic low back pain group (CLBPG, n=49) included 21 men and 28 women.
  
  
  METHODS
  Kinematic data were analyzed during six trunk movements: flexion, extension, left and right lateral bendings, and rotations under two pace conditions (preferred and fast paces).
  
  
  METHODS
  A three-dimensional optoelectronic motion analysis system was used to assess static (trunk inclinations and base of support) and dynamic (range of motion [ROM] and mean angular velocity of the trunk) parameters during the go and back phases of trunk movements.
  
  
  RESULTS
  In the initial position, CLBPG showed a more forward-tilted trunk inclination (2.1°±1.1°, p=.013) compared with CG. The base of support was significantly higher in CG (+22.7 cm2, p=.009) during the fast pace when compared with the preferred pace. Regardless of the pace condition, ROM and mean angular velocity of the trunk were significantly lower in CLBPG for all examined movements and the pace condition did not significantly alter ROM. At the preferred pace, both groups displayed the same motor strategy: they all went faster during the second phase of movement than during the first phase. However, at the fast pace, while CG was going faster during the first phase than during the second, CLBPG maintained the same motor strategy as at the preferred pace.
  
  
  CONCLUSIONS
  Contrary to CG who changed its motor behavior from a preferred pace to a fast pace, CLBPG exhibited freezing-like behaviors. This original result highlights the importance of studying the velocity. The use of this parameter may improve the diagnosis of CLBP patients and could be a key indicator for treatment progress and long-term monitoring.
authors: Univ Lille Nord de France, F-59000 Lille, France; UVHC, LAMIH, F-59313 Valenciennes, France; CNRS, UMR 8201, F-59313 Valenciennes, France; Centre de Rééducation Fonctionnelle La Rougeville, 59880 Saint-Saulve, France. Electronic address: bourigua.imen@gmail.com.
authors: Imen
authors: I
authors: Bourigua
authors: Univ Lille Nord de France, F-59000 Lille, France; UVHC, LAMIH, F-59313 Valenciennes, France; CNRS, UMR 8201, F-59313 Valenciennes, France.
authors: Emilie M
authors: EM
authors: Simoneau
authors: Univ Lille Nord de France, F-59000 Lille, France; UVHC, LAMIH, F-59313 Valenciennes, France; CNRS, UMR 8201, F-59313 Valenciennes, France; Centre de Rééducation Fonctionnelle La Rougeville, 59880 Saint-Saulve, France.
authors: Sébastien
authors: S
authors: Leteneur
authors: Univ Lille Nord de France, F-59000 Lille, France; UVHC, LAMIH, F-59313 Valenciennes, France; CNRS, UMR 8201, F-59313 Valenciennes, France.
authors: Christophe
authors: C
authors: Gillet
authors: Centre de Rééducation Fonctionnelle La Rougeville, 59880 Saint-Saulve, France.
authors: Ghassan
authors: G
authors: Ido
authors: Univ Lille Nord de France, F-59000 Lille, France; UVHC, LAMIH, F-59313 Valenciennes, France; CNRS, UMR 8201, F-59313 Valenciennes, France.
authors: Franck
authors: F
authors: Barbier
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009068:Movement; D011187:Posture; D016059:Range of Motion, Articular
keywords: Chronic low back pain; Diagnostic; Motor strategy; ROM; Trunk; Velocity