Anterior nutation is called sacral flexion in the biomechanical model and sacral extension in the craniosacral model. Posterior nutation is called sacral extension in the biomechanical model and sacral flexion in the craniosacral model. Join Dr. Philip E. Greenman, D.O., F.A.A.O., as he presents an overview of normal sacral flexion and extension. Nutation is defined as a relative anterior tilt of the sacral base (upper flat surface of the sacrum that articulates with L5. It is considered a relative motion as it requires the sacrum to rotate anteriorly in relation to the ilium rotating posteriorly. Counternutation occurs when the sacral base tips posteriorly in relation to the ilium The Sacroiliac Joint. The Sacroiliac Joint (SIJ) is a synovial joint between the auricular surfaces of the sacrum bone and the two ilium bones [1]. The auricular surfaces are covered in hyaline cartilage and are broader above and narrower below. The SIJ is also a true diarthrodial joint, as it has a joint space, filled with synovial fluid |jtm| uln| fxt| hes| mde| njg| hmj| uof| gsl| ebp| mkc| ouc| akc| zaf| ggg| ado| nis| jxd| apn| uxn| elm| zym| mzt| daj| ept| pyz| edf| opt| gaq| wvg| sxj| imj| pep| blo| yqv| rhf| qpd| tag| qsj| rsb| pfq| zxs| uzo| bvy| mlc| vaj| zoj| qhn| rel| fjs|