The anterior stress test, also called the gapping test, is performed with the patient supine.
The clinician stands to one side of the patient and, crossing the arms, places the palm of the hands on the patient’s anterior superior iliac spines.
The crossing of the arms ensures that the applied force is in a lateral direction, thereby gapping the anterior aspect of the sacroiliac joint. The stress is maintained for 30 seconds once an end-feel is obtained.
The procedure stresses the anterior (ventral) ligament and compresses the posterior aspect of the joint.
2. Posterior Sacroiliac Stress Test:
The posterior stress test, also called the compression test, is performed with the patient in the supine or sidelying position.
The clinician, standing behind the patient, applies a medial force to both innominates, using both hands. The stress is maintained for 30 seconds once an end-feel is obtained.
The procedure creates a medial force that tends to gap the posterior aspect of the sacroiliac joint, while compressing its anterior aspect.
The test also indirectly assesses the ability of the sacrum to counternutate.
The posterior (dorsal) SI ligament, which is accessible just below the posterior inferior iliac spine, should be palpated for tenderness.
What does a positive Sacroiliac Stress Test mean?
A positive test is one in which the patient’s groin or sacroiliac joint pain is reproduced anteriorly, posteriorly, unilaterally, or bilaterally.
Deep pain is a sign of strained anterior sacroiliac ligaments on the side of the pain (sacrospinous and sacrotuberous ligaments).
Pain in the buttocks can be produced by compression from the examining table or by irritation of the posterior portions of the sacroiliac joint.
Determining the precise location of the pain helps to identify its cause.
A positive stress test indicates the presence of inflammation, but does not give any information as to the cause.
If the test is positive in a patient who has recently fallen, there is a possibility that a fracture of the pelvis exists.
Sacroiliac joint becomes diseased in inflammatory conditions (seronegative inflammatory arthropathy), infections and fracture-dislocation. Special stress tests and other diagnostic tools can identify the pathology. Turning on bed especially in early morning hours and getting up from bed is very painful. Sometimes there can be pain on weightbearing with hamstring spasm.
Vleeming A, Pool-Goudzwaard AL, Hammudoghlu D, Stoeckart R, Snijders CJ, Mens JM. The function of the long dorsal sacroiliac ligament: its implication for understanding low back pain. Spine (Phila Pa 1976). 1996 Mar 1;21(5):556-62. doi: 10.1097/00007632-199603010-00005. PMID: 8852309.
Clinical Tests for the Musculoskeletal System 3rd Edition.
Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.
Clinical Assessment and Examination in Orthopedics, 2nd Edition Book