Pelvic Girdle & Axial Skeleton: Understanding Sacroiliac Joint Connections

The pelvic girdle, also known as the hip girdle, is attached to the axial skeleton by the sacroiliac joints. These joints are formed between the sacrum, which is the triangular bone at the base of the spine, and the ilium, which is the largest bone of the pelvis. The sacroiliac joints are synovial joints, which means that they are lined with a synovial membrane and filled with synovial fluid. This allows for smooth movement between the sacrum and the ilium.

The sacroiliac joints are supported by a number of ligaments, including the anterior sacroiliac ligament, the posterior sacroiliac ligament, and the interosseous sacroiliac ligament. These ligaments help to keep the sacroiliac joints in place and prevent them from moving too far in any direction.

The pelvic girdle is also attached to the axial skeleton by the sacrotuberous ligament and the sacrospinous ligament. These ligaments run from the sacrum to the ischium, which is the lower and back bone of the pelvis. The sacrotuberous ligament and the sacrospinous ligament help to support the pelvic girdle and prevent it from rotating too far in any direction.