Pelvis and SIJ
The sacroiliac (SI) joint is located in the pelvis. It links the iliac bone (pelvis) to the sacrum (lowest part of the spine above the tailbone).
The main function of the SI joint is to provide stability and attenuate forces to the lower extremities especially in squatting, hinging and lunging movements . The strong ligamentous system of the joint makes it better designed for stability and limits the amount of motion available. This joint transfers weight and forces between your upper body and legs. It is an essential component for energy transfer between the legs and the torso.
The sacroiliac joint (SIJ) is unique in that it is a transitional joint between the sacrum of the spine (axial body) and the ilium of the pelvic bone of the lower extremity.
The SI joint is stabilized by a network of ligaments and muscles, which also limit motion. The normal sacroiliac joint has a small amount of normal motion of approximately 2-4 mm of movement in any direction.
The SIJ does two key motions, nutation and counternutation.
Nutation – occurs as the sacrum moves anteriorly and inferiorly while the coccyx moves posteriorly relative to the ilium like in a deadlift of hinge movement.
Counternutation – occurs as the sacrum moves posteriorly and superiorly while the coccyx moves anteriorly relative to the ilium like in a squat position. This motion is opposed by the posterior sacroiliac ligament that is supported by the multifidus.
It is very important to note that this motion is lost due lower back tightness and ligamentous stiffness as a result of sitting.
The Waveblade centre blades are specifically designed to engage with the ligaments in the SIJ and improve and restore flexibility and mobility.