title: [The application of three dimensional analysis system in measuring rotation angles of thumb carpometacarpal joints].
abstract: OBJECTIVE
  To measure the axial rotation angles of the carpometacarpal joints during the digital opposition of thumb-index finger, thumb-medial finger, thumb-ring finger, thumb-little finger and the thumb's maximal opposition, then the application of these parameters were studied.
  
  
  METHODS
  Twenty neutrality-occupation volunteers (female 10, male 10) with no history of hand injuries or related diseases were involved in the study. First, all the markers' 3-D coordinates were obstained using the 3D motion analysis system (EVaRT4.1) during the digital opposition movements of thumb. Then, the axial rotation angles were calculated.
  
  
  RESULTS
  The average rotation angles of carpometacarpal joints during all kinds of digital oppositions were 29.1 degrees +/- 9.4 degrees (male), 24.8 degrees +/- 10.2 degrees (female), while the maximal rotation angles are: 35.3 degrees (male), 28.8 degrees (female).
  
  
  CONCLUSIONS
  The combination of video-based 3-D analysis system and mathematics make it possible to measure the axial rotation angles of thumb in vivo, as a result, the rotation angles of thumb carpometacarpal joints are measured precisely for the first time. These results can provide a few parameters for treatment and rehabilitation of carpometacarpal arthrositis.
authors.affiliation: Department of Orthopaedic Surgery, Nantong University, Nantong 226001, China. liufan19575@yahoo.com.cn
authors.forename: Fan
authors.initials: F
authors.lastname: Liu
authors.forename: Wen-feng
authors.initials: WF
authors.lastname: Zhu
authors.forename: Guo-feng
authors.initials: GF
authors.lastname: Bao
authors.forename: Jian-an
authors.initials: JA
authors.lastname: Li
authors.forename: Zhi-ming
authors.initials: ZM
authors.lastname: Gu
authors.forename: Dian-huai
authors.initials: DH
authors.lastname: Meng
authors.forename: Mo-ye
authors.initials: MY
authors.lastname: Fang
authors.forename: De
authors.initials: D
authors.lastname: Shi
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging* / Q000502:physiology; D005471:Fluoroscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008297:Male; D009068:Movement / Q000502:physiology; D015203:Reproducibility of Results