Reliability of quality measures of movement in lumbar spine flexion-extension radiography.
BACKGROUND
For center of rotation (COR) and centroid length variables in lumbar flexion-extension radiography, enough reliability information is not available.


OBJECTIVE
The objective of this study was to determine the intra-rater reliability of COR and centroid length of lumbar intervertebral movement.


METHODS
A methodological research for reliability was designed. Fifteen males with chronic non specific low back pain aged between 22-43 years participated in this study. Study variables included COR of full, flexion and extension arc and centroid length. The proposed method from Putto was used for flexion-extension radiography. Five x-rays were taken in neutral, full flexion and extension, mid-flexion and mid-extension positions. The variables were calculated using Computer Aided Radiographic Analysis of Spine (CARA) software after scanning. The intraclass correlation coefficient (ICC) and standard error of measurement (SEM) were utilized for relative and absolute reliability respectively.


RESULTS
The results demonstrated high ICC values on x axis (range: 0.67-0.88) and y axis (range: 0.55-0.90) for full arc COR, high ICC values of flexion arc COR on x axis (range: 0.54-0.97) and y axis (range: 0.48-0.99). ICC values results of extension arc ranged between 0.19-0.60 for x axis and 0.16-0.83 for y axis. ICC values for centroid length ranged between 0.22-0.88.


CONCLUSIONS
Results support previous studies which show very high reliability of full arc COR. In addition, flexion arc COR has desirable reliability and low measurement errors. But, extension arc COR and centroid length have moderate reliability and large measurement errors.
Taghipour-Darzi
Mohammad
M
Department of Physiotherapy, Faculty of Medicine, Babol University of Medical Sciences, Babol, Mazandaran, Iran. taghipourm@yahoo.com
Ebrahimi-Takamjani
Esmail
E
Salavati
Mahyar
M
Mobini
Bahram
B
Zekavat
Hajar
H
D000328:Adult; D001175:Arthrography / Q000592:standards* / Q000706:statistics & numerical data; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000592:standards*; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D055815:Young Adult