Paradigm for assessment and treatment of SIJ mechanical dysfunction.

The sacroiliac joint (SIJ) is an integral part of both the lumbar spine and the pelvic girdle. It is frequently the source of low back pain and pelvic girdle pain. Recent research has permitted a deeper understanding of its function and assessment. The mechanical assessment of the SIJ as a transmitter of load between trunk and lower limbs, and as a means to absorb torsion stresses of the pelvis absorber of torsion is examined; history, clinical examination and imaging modalities are explored and the role of exercise and some interventional therapies are described in general terms.