title: [Reliability research of spine stiffness test system].
abstract: OBJECTIVE
  To investigate the reliability of the spine stiffness test system (SSTS) by animal experiments.
  
  
  METHODS
  A hundred SD male rats with weight body of 350-450 g were divided randomly into 5 groups according to feeding time of 1, 2, 4, 8,12 weeks. The externally linked fixation systems were implanted into all rats in L4, L5, and L6. At the end of every feeding time, the stiffness of the fixed segment was measured by SSTS, and the relationship between linking time and the stiffness were observed. The parameters of pressure sensor of SSTS were demarcated before measuring the stiffness in order to ensure the accuracy of SSTS.
  
  
  RESULTS
  The actual error of the spine stiffness test system was less than 0.04%. Its reliability was good, ICC = 0.948 (P < 0.01). And the stiffness of the fixed segment increased with linking times.
  
  
  CONCLUSIONS
  The accuracy and reliability of SSTS were good. Its operating system was very simple to manipulate. And SSTS may accurately collect pressure load and infinitesimal displacement of the spinal motion segment. In order to fit more spinal injuries models, SSTS needs improvements in fixed accessories, measurement range, disturbance variable, and so on.
authors.affiliation: The Institute of Massage of Yueyang Hospital of Integrative Chinese & Western Medicines Affiliated to Shanghai University of TCM, Shanghai 200437, China.
authors.forename: Ling-Jun
authors.initials: LJ
authors.lastname: Kong
authors.forename: Wei-An
authors.initials: WA
authors.lastname: Yuan
authors.forename: Ying-Wu
authors.initials: YW
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D008297:Male; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013131:Spine / Q000502:physiology*