Sacrococcygealis

Sacrococcygealis refers to a small, variable muscle found in humans and other primates that attaches the sacrum to the coccyx. It is often considered part of the multifidus muscle group, which runs along the spine. The precise origin and insertion of the sacrococcygealis can vary, but it generally originates from the posterior surface of the sacrum and inserts onto the anterior or lateral surface of the coccyx.

This muscle plays a role in stabilizing the sacrococcygeal joint and may contribute to the slight movements of the coccyx. Its presence and size can differ significantly among individuals. In some cases, the sacrococcygealis may be absent, or it might be fused with other muscles in the region. Due to its small size and variable nature, the sacrococcygealis is not typically considered a major contributor to gross motor function. Its anatomical significance is primarily in its contribution to the complex musculature of the pelvic floor and the lower vertebral column. Research on the sacrococcygealis is less extensive than on larger, more prominent muscles.