

The Gillet Test is also known under the names of Marching Test or Sacral Fixation Test. The test was designed to detect sacroiliac joint dysfunction, which is defined as a sacroiliac joint that is “blocked” and thus not moving. However, like many other palpation tests, the Gillet test has a low reliability with a kappa value of 0.22 according to Dreyfuss et al. in the year 1996. The same authors report a sensitivity of 43% and a specificity of 68%. So altogether, the value of this test is questionable in practice.
To perform the test, position yourself behind your patient and palpate both posterior superior iliac spines, which are at the height of the spinous process of S2. To test the right SI joint keep your right hand on the PSIS and the left hand palpates S2. Now, ask your patient to flex his right hip to 90°. In a normal SI joint, the PSIS will drop below S2. In a dysfunctional SI joint that is “blocked” or hypomobile, you will see that the PSIS will not drop or move only minimally.
Other orthopedic tests for SIJ dysfunction are:
Due to the low reliability of SIJ dysfunction test, we advise leaving them behind and only focusing on SIJ provocation tests like the cluster of Laslett.