A Radiostereometric Analysis of Movements of the Sacroiliac Joints During the Standing Hip Flexion Test

The small movements registered support the theory of form and force closure in the sacroiliac joints. The self-locking mechanism that goes into effect when the pelvis is loaded in a one-leg standing position probably obstructs the movements in the sacroiliac joints. Therefore, the standing hip flexion test cannot be recommended as a diagnostic tool for evaluating joint motion in the sacroiliac joints.