Diagnosis of sacroiliac joint (SIJ) dysfunction is made primarily by clinical examination using various special tests as preliminary diagnostic tools. These screening tests are used to assess the asymmetry of sacroiliac motion, which is thought to be due to a relative, unilateral hypomobility of one side of the SIJ. The occurence of positive tests has not been thoroughly investigated in an asymptomatic population. The purpose of the study is two fold: 1) to determine if commonly used SIJ screening tests may be positive in asymptomatic individuals, and 2) to determine if a relationship exists between rectus femoris and hamstring muscle tightness and results of the SIJ tests. Subject: A sample of convenience consisted of 50 asymptomatic adults from 18 to 50 years of age. Methods: A prospective study that investigated the occurence of positive sacroiliac joint screening tests including the standing flexion test, the supine to long sitting test, and the prone knee flexion test in asymptomatic individuals. The primary examiner performed the three SIJ tests on all subjects. A secondary tester tested the hamstring and rectus fermoris muscles length. Data analysis: Chi-square values and P values were calculated using a one-sample test to determine the association between the hamstring and rectus femoris muscle tightness and the presence of positive SIJ screening tests. Results: Overall, 18% of subjects were judged to have a positive test for at least one of the 3 SIJ screening tests. There was no relationship between hamstrings or rectus femoris muscle tightness and positive SIJ screening tests. Discussion and Conclusion: Positive sacroiliac screening tests can occur in asymptomatic individuals. Clinicians need to be aware of thsi during routine physical therapy assessment. There appears to be no relationship between hamstrings or rectus femoris muscle tightness and positive SIJ screening tests.
