Interobserver Reliability of Neck-Mobility Measurement by Means of the Flock-of-Birds Electromagnetic Tracking System

• Published in: Journal of manipulative and physiological therapeutics Vol. 28; no. 6; pp. 408 - 413
• Main Authors: Assink, Nienke, Bergman, Gert J.D., Knoester, Bianca, Winters, Jan C., Dijkstra, Pieter U., Postema, Klaas
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.07.2005
• Subjects: Adult; Cervical Vertebrae - physiopathology; Electromagnetic Phenomena - methods; Female; Humans; Male; Middle Aged; Neck - physiopathology; Observer Variation; Range of Motion, Articular; Reproducibility of Results; Rotation; Shoulder - physiopathology; Spinal Diseases - physiopathology; Measurement; Reproducibility of Results; Cervical Vertebrae; Interobserver Variation; Articular; Range of Motion
• ISSN: 0161-4754; 1532-6586; 1532-6586
• DOI: 10.1016/j.jmpt.2005.06.009

To establish the interobserver reliability for measuring neck mobility in human subjects by means of an electromagnetic tracking device, the Flock-of-Birds system. Two observers independently and in random order assessed the cervical range-of-motion in 30 subjects with a dysfunction in the neck and shoulder region (symptomatic subjects) and 30 subjects without known pathology (asymptomatic subjects). Measurements included rotation in neutral position, in flexed position and in extended position, flexion-extension, and lateral bending (all active and passive). Reliability was analyzed by intraclass correlation coefficient (ICC) and agreement by limits of agreement and percentage of paired observations within 5°, 10°, and 15°. For asymptomatic subjects, the ICC varied from 0.57 to 0.85, and the limits of agreement varied between 14.5° and 27.0°.The percentage of paired observations within 5°, 10°, and 15° ranged from 31% to 57%, 58% to 90%, and 78% to 93%, respectively. For symptomatic subjects, the ICC varied from 0.36 to 0.91, and the limits of agreement varied between 9.6° and 37.8°. The percentage of paired observations within 5°, 10°, and 15° ranged from 17% to 60%, 33% to 93%, and 50% to 97%, respectively. Despite the use of a standardized protocol and a sophisticated measurement system, the interobserver reliability of neck mobility was variable in quality, with reliability being good in rotation in neutral position, flexion-extension, and lateral bending. (J Manipulative Physiol Ther 2005;28:408-413)