title: The use of electromagnetic tracking technology for measurement of passive cervical range of motion: a pilot study.
abstract: OBJECTIVE
  To investigate the use of electromagnetic tracking technology for measurement of passive cervical range of motion (ROM).
  
  
  METHODS
  Passive cervical ranges of motion from one extreme to the other were measured in 3 planes (transverse, frontal, and sagittal) by using an electromagnetic tracking system (ETS), the cervical range of motion device (CROM), and visual estimation (VE) with 2 blinded examiners, using a repeated measures design.
  
  
  METHODS
  Swinburne University of Technology, Australia.
  
  
  METHODS
  Four studies were undertaken: (1) Measurement of ROM using 3 methods: the CROM, the ETS, and VE. Two examiners conducted measurements. (2) Measurement of ROM with the CROM and the ETS simultaneously by 1 examiner. (3) Measurement of ROM with the ETS by 2 examiners. (4) Measurement of medium-term reliability of ROM using the ETS over a 24-hour period by 1 examiner.
  
  
  METHODS
  The intraclass correlation coefficient (ICC) was used to investigate the reliability within and between each method and reliability of ROM over a 24-hour period.
  
  
  RESULTS
  Study 1: Intra-instrument ICCs ranged from fair to high for the 3 measurement methods. The ETS performed best. Inter-instrument ICCs were poor. Study 2: Direct comparison of the ETS and the CROM yielded high ICCs for rotation and flexion/extension and fair for lateral flexion. Study 3: Interexaminer ICCs using the ETS were high for rotation, good for lateral flexion, and fair for flexion/extension; intraexaminer reliability was high for all planes. Study 4: 24-hour reliability of ROM using the ETS was good for rotation and lateral flexion and poor for flexion/extension.
  
  
  CONCLUSIONS
  The ETS used in this investigation was an accurate instrument and efficient method for measurement and recording of passive cervical ROM. The ETS had high intraexaminer and fair-to-high interexaminer reliability for the measurement of extremes of ROM in 3 planes. It is probable that differences in the experience levels of examiners did affect interexaminer reliability of the ETS. The ETS and the CROM compared well in rotation and flexion/extension.
authors.affiliation: School of Science and Engineering, Swinbourne University of Technology, Melbourne, Australia. adrian_morphett@hotmail.com
authors.forename: Adrian Lindsay
authors.initials: AL
authors.lastname: Morphett
authors.forename: Colin M
authors.initials: CM
authors.lastname: Crawford
authors.forename: Don
authors.initials: D
authors.lastname: Lee
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002574:Cervical Vertebrae / Q000502:physiology; D002684:Chiropractic / Q000379:methods*; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D016059:Range of Motion, Articular; D012016:Reference Values; D015203:Reproducibility of Results; D012399:Rotation