Changes in Innominate Tilt After Manipulation of the Sacroiliac Joint in Patients with Low Back Pain

The purposes of this study were to 1) propose a method to detect sacroiliac joint dysfunction (SIJD), 2) test the interrater reliability of the method on a group of patients with low back pain (LBP), and 3) document changes in innominate tilt after manipulation of the sacroiliac joint. Criteria for SIJD were established by the authors. Twenty-six patients with unilateral LBP were examined independently for presence of SIJD by two examiners. Interrater agreement for presence or absence of SIJD was found to be excellent (Cohen's Kappa = .88). Twenty of the patients who met the criteria for SIJD were randomly assigned to an Experimental Group (n = 10) or a Control Group (n = 10). The left and right innominate bones of these 20 patients were measured for tilt before and after the intervention period. The sacroiliac joint of the patients in the Experimental Group was manipulated during the intervention period, whereas the patients in the Control Group received no treatment. Data were analyzed using a mixed three-factor analysis of variance. The data analysis revealed that the manipulation procedure resulted not only in an altered innominate tilt of the same side but also in an equal and opposite tilt of the opposite side (F = 67.07; df = 1.18; p less than .05). The results indicate that SIJD can be identified reliably in patients with LBP and that a manipulative procedure purported to be specific to the sacroiliac joint changes innominate tilt bilaterally and in opposite directions.