What is the significance of palpating the PSIS during the standing flexion test?

Palpating the posterior superior iliac spine (PSIS) during the standing flexion test is crucial for determining movement dysfunction between the sacroiliac joints or assessing potential asymmetries in pelvic movement. This test is designed to evaluate the mobility of the sacroiliac joints and to check for any dysfunction in that area.

During the test, the therapist observes the movement of the PSIS as the patient bends forward. A positive finding would indicate that one PSIS moves differently compared to the other, suggesting that there is a dysfunction—such as hypomobility or instability—on one side of the pelvis. Movement dysfunction can lead to various issues, including pain and altered function in the lumbar spine and pelvis, making it important for clinicians to identify and address these issues in rehabilitation or treatment programs.

This assessment promotes an understanding of how the pelvis and lumbar spine interact during movement, which can inform the clinician about potential compensation patterns and aid in devising appropriate treatment strategies.