Low back pain has been the subject of extensive research in the past 10 years. Some of the efforts have focused on the effectiveness of diagnostic testing in determining the etiology of low back pain. One component of low back pain clinically can be sacroiliac joint (SIJ) dysfunction. The prevalence of sacroiliac pain in the low back pain population is reported to be approximately 10 to 30%. The diagnosis of sacroiliac pain has been an area of controversy in the literature with poor inter-tester and intra-rater reliability described for motion testing. More recently, a cluster of provocation tests has been described as predictive of the diagnosis of sacroiliac dysfunction. Laslett et al suggested that SI pain provocation tests used in examination should include a cluster of six tests. When three or more out of six tests or any two of four selected tests are positive, that showed the best predictive power in diagnosing SIJ pain. The "gold standard" for diagnosing SIJ pain in this study was pain relief with intra-articular local anesthetic block injection. When all six provocation tests do not provoke the patient's typical pain, the SIJ can be ruled out as a source of current low back pain.