REACTIVITY OF LEG ALIGNMENT TO ARTICULAR PRESSURE TESTING - EVALUATION OF A DIAGNOSTIC-TEST USING A RANDOMIZED CROSSOVER CLINICAL-TRIAL APPROACH

Objective: A study was undertaken to assess the reliability of detecti ng leg alignment changes (reactivity) and to determine if the observed leg alignment reactivity can be attributed to a rotatory articular pr essure challenge. Design: Prospective double-blind crossover trial of a diagnostic test. Setting: Laboratory: Center for Technique Research. Participants: Forty-two chiropractic college students, faculty and st aff. Interventions: A standardized force of 2 or 3 kg was applied with a 1 cm2 rubber-tipped pressure algometer on the lateral aspect of the T3-T7 spinous processes and the posterior aspect of the lateral masse s of C 1. Main Outcome Measures: Leg alignment reactivity: an increase in leg alignment discrepancy (yes or no) following a diagnostic inter vention. Results: The reliability for detecting leg alignment reactivi ty was poor: on average, Kappa = 0.05 in the thoracics and 0.06 at Cl. On average, the attributable risk of leg alignment reactivity (pressu re test risk - sham test risk) was less than 4%. In many cases, the sh am rate was greater than the pressure test rate. Conclusions: For the population investigated, leg alignment reactivity to rotatory pressure testing can, in the majority of cases. be attributable to background noise. This procedure was not found to be viable for identifying verte brae for adjustment. Further research with different subject populatio ns, regions of investigation, leg alignment measurement techniques and vertebral challenge techniques are indicated.