Reliability of spinal motion palpation is enhanced when raters are confident about their calls: Preliminary findings

Motion Palpation (MP) is commonly used to assess spinal intersegmental hypomobility/hypermobility, although literature reviews on its reliability have reported only slight interexaminer reliability and moderate intraexaminer reliability. Previous MP reliability studies have assumed that each subject had fixations, with some studies requiring a forced call on all subjects, even those who did not have a significant fixation. In an effort to minimize the effect of forced calls in this type of study, we allowed a confidence vote on each of the raters' calls, not eliminating subjects, but segregating them into categories of confidence. Accordingly, the purpose of this study was to determine the effect confidence calls had on the inter-examiner reliability of thoracic MP.

Subjects were 19 asymptomatic chiropractic students who were selected by convenience. Examiners were licensed chiropractors, each with more than 20 years of clinical experience. Both raters and patients were blinded and the order of raters was randomized. After a fixation was located, the rater made a confidence call and placed a marker on the subject's skin; then the distance from the S1 spinous process to the marker was measured. The marker was removed before the next rater's evaluation.

Reliability was high when both raters were confident in their findings (ICC [3,1] 0.806; 95% CI 0.301 to 0.958), although it was very poor when either one or both raters were not confident (ICC [3,1] -0.499; 95% CI -0.835 to 0.109). Thus, the confidence level of raters' calls does appear to influence the reliability of thoracic MP.