RESPONSIVENESS OF LEG ALIGNMENT CHANGES ASSOCIATED WITH ARTICULAR PRESSURE TESTING TO SPINAL MANIPULATION - THE USE OF A RANDOMIZED CLINICAL-TRIAL DESIGN TO EVALUATE A DIAGNOSTIC-TEST WITH A DICHOTOMOUS OUTCOME
M. Haas et al., RESPONSIVENESS OF LEG ALIGNMENT CHANGES ASSOCIATED WITH ARTICULAR PRESSURE TESTING TO SPINAL MANIPULATION - THE USE OF A RANDOMIZED CLINICAL-TRIAL DESIGN TO EVALUATE A DIAGNOSTIC-TEST WITH A DICHOTOMOUS OUTCOME, Journal of manipulative and physiological therapeutics, 16(5), 1993, pp. 306-311
Objective: A study was undertaken to assess the stability of leg align
ment reaction to a pressure challenge and its responsiveness to an adj
ustive intervention. Design: Prospective, double-blind clinical trial
of a diagnostic test. Setting: Laboratory: Center for Technique Resear
ch. Participants: Forty-two chiropractic college students, faculty and
staff. Interventions: A high-velocity, low-amplitude, short lever adj
ustment of a single vertebra from among C1 and T3-T7; or a sham adjust
ment similar to a manual diagnostic pressure test at C1, T3-T7 or T9-T
10. Main Outcome Measures: Leg alignment reactivity: An increase in le
g alignment discrepancy (yes or no) following a metered pressure chall
enge to a vertebra. Results: On average, stability was poor at T3-T7 (
Kappa = 0.04), moderate at C1 (K = 0.47), and fair for sham pressure t
ests (K = 0.30). Responsiveness: The proportion of positive baseline l
eg alignment reactions that responded (became negative) to sham adjust
ment was 95% at T3-T7 and 55% at Cl. Further analysis was untenable si
nce too few vertebrae were implicated for an adjustment. Conclusions:
For the population investigated, the majority of the responsiveness of
the leg alignment diagnostic test to a rotatory adjustment appears to
be a diagnostic illusion (i.e., background noise unrelated to a treat
ment intervention). Further research with different subject population
s, regions of investigation, leg alignment measurement techniques and
vertebral challenge techniques are indicated.