title: [Radiographic studies of cervical spine motion range in normal Chinese subjects with computer-assisted image analysis: full flexion and extension].
abstract: OBJECTIVE
  To study the degenerative regularity of normal Chinese cervical spine by observing the motion range of full cervical flexion and extension, and to provide evidences for further investigation of cervical segmental instability.
  
  
  METHODS
  764 X-ray plain films of full cervical flexion and extension in 382 normal Chinese subjects (214 were male and 168 female) were investigated using self-designed cervical X-ray image analysis system. The subjects within the same sex group were divided into three groups according to the age: group A (20 years to 39 years), group B (40 years to 59 years) and group C (60 years to 76 years). During the full cervical flexion and extension motion, total intervertebral motion range (from C(2) - C(3) to C(6) - C(7)) and intervertebral motion range at each level were major parameters.
  
  
  RESULTS
  The range of total intervertebral motion showed much greater mobility in group A than in group B and group C (P < 0.01) but no statistically significant difference between group B and group C (P > 0.05). The range of intervertebral motion was maximal at C(5) - C(6) in group A. The place of maximal motion shifted to the C(4) - C(5) in both group B and group C. C(2) - C(3) showed minimal mobility in all three groups. There was no statistically significant difference (P > 0.05) between male and female.
  
  
  CONCLUSIONS
  The motion range and degenerative regularity of normal Chinese cervical spine were similar in either sex. The range of total intervertebral motion (from C(2) - C(3) to C(6) - C(7)) had a tendency to decrease rapidly and then became steady with age. For the range of intervertebral motion, the place of maximal motion shifted to the higher level with age from C(5) - C(6) in group A to C(4) - C(5) in group B and group C.
authors.affiliation: Department of Orthopaedics, Third Teaching Hospital, Beijing Medical University, Beijing 100083, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Qi
authors.forename: G
authors.initials: G
authors.lastname: Dang
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Pan
authors.forename: S
authors.initials: S
authors.lastname: Ma
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D019411:Clinical Laboratory Techniques; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009333:Neck; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*