title: Reliability of segmental accelerations measured using a new wireless gait analysis system.
abstract: The purpose of this study was to determine the inter- and intra-examiner reliability, and stride-to-stride reliability, of an accelerometer-based gait analysis system which measured 3D accelerations of the upper and lower body during self-selected slow, preferred and fast walking speeds. Eight subjects attended two testing sessions in which accelerometers were attached to the head, neck, lower trunk, and right shank. In the initial testing session, two different examiners attached the accelerometers and performed the same testing procedures. A single examiner repeated the procedure in a subsequent testing session. All data were collected using a new wireless gait analysis system, which features near real-time data transmission via a Bluetooth network. Reliability for each testing condition (4 locations, 3 directions, 3 speeds) was quantified using a waveform similarity statistic known as the coefficient of multiple determination (CMD). CMD's ranged from 0.60 to 0.98 across all test conditions and were not significantly different for inter-examiner (0.86), intra-examiner (0.87), and stride-to-stride reliability (0.86). The highest repeatability for the effect of location, direction and walking speed were for the shank segment (0.94), the vertical direction (0.91) and the fast walking speed (0.91), respectively. Overall, these results indicate that a high degree of waveform repeatability was obtained using a new gait system under test-retest conditions involving single and dual examiners. Furthermore, differences in acceleration waveform repeatability associated with the reapplication of accelerometers were small in relation to normal motor variability.
authors.affiliation: School of Physiotherapy and Exercise Science, Griffith University, PMB 50 Gold Coast Mail Centre 9726, Gold Coast, Queensland, Australia. j.Kavanagh@griffith.edu.au <j.Kavanagh@griffith.edu.au>
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Kavanagh
authors.forename: Steven
authors.initials: S
authors.lastname: Morrison
authors.forename: Daniel A
authors.initials: DA
authors.lastname: James
authors.forename: Rod
authors.initials: R
authors.lastname: Barrett
mesh_terms: D000054:Acceleration; D000328:Adult; D003625:Data Collection / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012107:Research Design; D013223:Statistics as Topic; D016138:Walking / Q000502:physiology