Related Experiment Video
Updated: Jul 17, 2025

Clinical Application of Microscope-Assisted Minimally Invasive Anterior Lumbar Interbody Fusion
Published on: June 16, 2023
Inter-Examiner Agreement of the National Upper Cervical Chiropractic Association Analysis of the Atlas Subluxation
Jordan Landholm-Duvall1, D Gordon Hasick1, Harrison Ndetan2
1Upper Cervical Research Foundation, Minneapolis, Minnesota.
Objective:
The purpose of this study was to measure the inter-examiner agreement between radiograph markings of 2 National Upper Cervical Chiropractic Association board-certified chiropractors.
Methods:
Two chiropractic examiners who had standardized training marked and analyzed 254 conventional orthogonal radiographic film sets. The level of agreement and potential biases in their measurements were assessed using intraclass correlation coefficients for absolute agreement and Bland-Altman plot analyses.
Results:
There was 96.1% agreement between the examiners in the measurements of the side of atlas laterality and 94.5% for atlas rotation. The intraclass correlation coefficient was 0.95 (95% CI, 0.93-0.96) for atlas laterality and 0.92 (95% CI, 0.89-0.94) for atlas rotation. The mean difference in the measurement between the 2 examiners was -0.11, P = .12 for atlas laterality and 0.05, P = .55 for atlas rotation. Neither atlas laterality nor atlas rotation measurements were significantly different from zero. Bland-Altman plots were not suggestive of any proportional biases in the 2 measurements.
Conclusion:
Results of this study show almost perfect agreement between 2 trained chiropractic examiners, with no apparent proportional bias in the analysis of conventional orthogonal radiographic film sets.
Related Concept Videos
Articulations of the Vertebral Column
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
