title: The effect of cervical traction combined with rotatory manipulation on cervical nucleus pulposus pressures.
abstract: OBJECTIVE
  To study experimentally the effect of cervical traction combined with rotatory manipulation on the pressure of the cervical nucleus pulposus.
  
  
  METHODS
  Randomized experimental study.
  
  
  METHODS
  Institute of Clinical Anatomy and Biomechanics, the First Military Medical University, GuangZhou, China.
  
  
  METHODS
  Twelve fresh cervical spines, from C7 to occipital bone, were obtained from cadavers of patients who had died from acute brain death.
  
  
  METHODS
  State A: under different traction forces, the cervical spine was rotated. State B: the cervical spine was rotated first and then tractioned. State C: the cervical spine was tractioned and rotated simultaneously.
  
  
  METHODS
  The cervical spine was tractioned and rotated by the Material Test System (MTS), and pressures of the cervical nucleus pulposus of C3-4, C4-5 and C5-6 were measured using pressure sensors.
  
  
  RESULTS
  (a) When the traction force increased, the pressure fell continuously in the 200-N tractioned spines; the pressure increased slightly when the sample was rotated. (b) The pressure fell to a certain extent when the state of cervical spine was restored. (c) In state A, the pressure fell obviously and increased slightly under a 200-N traction force and then the sample was rotated; in state B, the pressure first increased to a certain extent and then fell slightly and in state C, the pressure underwent no change in the main.
  
  
  CONCLUSIONS
  The results of this research suggest that rotatory manipulation of cervical spine under traction was the safest of the three procedures and the traction force used in clinical treatment may be a little smaller.
authors.affiliation: Institute of Clinical Anatomy and Biomechanics, People's Liberation Army, First Military Medical University, GuangZhou, People's Republic of China. biomech@fjnet.guangzhou.gd.cn
authors.forename: Y K
authors.initials: YK
authors.lastname: Li
authors.forename: Q A
authors.initials: QA
authors.lastname: Zhu
authors.forename: S Z
authors.initials: SZ
authors.lastname: Zhong
mesh_terms: D002574:Cervical Vertebrae / Q000502:physiology*; D006801:Humans; D008349:Manipulation, Orthopedic; D011312:Pressure; D011897:Random Allocation; D014143:Traction