Establishing the content validity of palpatory examination for the assessment of the lumbar spine using ultrasonography: a pilot study.

CONTEXT

Practitioners of manipulative medicine have long sought to prove the intra- and interexaminer reliability of palpatory examinations in assessing somatic dysfunction. However, decades of research have yet to achieve the level of reproducibility needed to satisfy evidence-based criteria.

OBJECTIVES

To examine the content validity of segmental motion evaluations using ultrasonographic measurements and to investigate the implication of these results for understanding the effects of an osteopathic manipulative treatment technique--high-velocity, low-amplitude (HVLA)--applied to somatic dysfunction in the lumbar spine.

METHODS

A repeated-measures design was used, with the ultrasonographer blinded to the findings for each participant. The study was divided into 2 phases: (1) palpatory and ultrasonographic examination with no treatment and (2) palpatory and ultrasonographic examination with HVLA treatment. During phase 1, measurements were taken of tissue depth corresponding to bony landmarks of the dysfunctional vertebrae. Dysfunction was identified by means of palpatory examination and captured in sequential (ie, test-retest) ultrasonographic images. Content validity of somatic dysfunction was addressed by comparing palpatory examination with ultrasonographic data. During phase 2, the same protocol for tissue depth measurements was applied to the pre- and posttreatment images for comparison.

RESULTS

Twelve young, healthy, asymptomatic students with no contraindications to HVLA treatment were recruited at Kansas City University of Medicine and Biosciences. The test-retest reliability, as determined by a Pearson correlation coefficient, was 0.997. For all participants, objectively identified side of dysfunction correlated with palpatory evaluation of segmental motion. A within-subjects analysis of variance was performed on the raw data, corrected for lumbar lordosis, showing statistical significance for main effect for side of measurement (P<.001) and interaction of side and time (P<.001), and showed no statistically significant effect for time (P=.259).

CONCLUSION

Ultrasonography is a reliable instrument for the assessment of somatic dysfunction of the lumbar spine. The data also establish the content validity of palpatory examinations. In addition, this study provides the first objective evidence, to our knowledge, of the effect of a thrusting manipulative treatment on dysfunctional lumbar vertebrae.