title: Stability and intra-tester reliability of an in vivo measurement of thoracic axial rotation using an innovative methodology.
abstract: The aim of this study was to evaluate the stability and intra-tester reliability of an innovative approach to measure active thoracic spine axial rotation. Ultrasound imaging of a thoracic vertebra in conjunction with Polhemus motion analysis of the transducer was used to measure axial thoracic spine rotation in a functional position. The range of motion in a convenience sample of asymptomatic subjects (n=24) was calculated across ten repetitions of a single trial to evaluate stability. The protocol was repeated the same day and 7-10 days later to provide data for within and between day intra-tester reliability. Mean total range of axial rotation was 85.15 degrees across a single trial with SD=14.8, CV=17.4, SEM=3.04. SEM ranged 0.63-3.37 for individual subjects and 2.60-3.64 across repetitions. Stability of performance occurred at repetitions 2-4. Intra-tester reliability (ICC(2,1)) was excellent within day (0.89-0.98) and good/excellent between days (0.720.94). Bland-Altman plots however suggest that agreement may range from 0 to 10% for within day measures and from 0 to 15% for between day measures. Whether this combined approach has sufficient precision and accuracy as a clinical research tool has yet to be fully evaluated.
authors.affiliation: School of Sport and Exercise Sciences, University of Birmingham, Birmingham, B15 2TT, UK. n.heneghan@bham.ac.uk
authors.forename: Nicola R
authors.initials: NR
authors.lastname: Heneghan
authors.forename: Alison
authors.initials: A
authors.lastname: Hall
authors.forename: Mark
authors.initials: M
authors.lastname: Hollands
authors.forename: George M
authors.initials: GM
authors.lastname: Balanos
mesh_terms: D000293:Adolescent; D000328:Adult; D053587:Arthrometry, Articular / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012399:Rotation; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging*; D014463:Ultrasonography