Interexaminer reliability of an isolation test for the identification of cervical subluxation

A reliability study was conducted to determine whether prone leg length analysis in association with an isolation test maneuver was reproducible. Seventy-two subjects were evaluated by two examiners on separate occasions for the presence of C1 subluxation. Concordance was assessed by the Kappa statistic, and interexaminer percentage of agreement was compared. Agreement beyond chance for the two groups was K = 0.52, p less than 0.01 and 0.55, p less than 0.001, respectively. The results indicate good reliability using this method of analysis for putative upper cervical subluxation in this patient population. Further investigation is necessary to correlate this method of analysis with the empirical evidence of manipulable lesions or subluxations.