Extensor coccygis

Extensor Coccygis

Theextensor coccygis is a small, often overlooked muscle located in the human body. It is part of the group of muscles associated with the coccyx, or tailbone, which is the terminal segment of the vertebral column. This muscle plays a role in the movement and stabilization of the coccyx.

Anatomy

The extensor coccygis is a slender muscle that originates from the lower sacral vertebrae and inserts into the coccyx. It is situated posteriorly, lying over the sacrococcygeal joint. The muscle fibers run longitudinally along the dorsal aspect of the coccyx.

Origin and Insertion

• Origin: The extensor coccygis originates from the lower sacral vertebrae, specifically from the posterior surface of the sacrum.
• Insertion: It inserts into the dorsal surface of the coccyx.

Nerve Supply

The nerve supply to the extensor coccygis is provided by the sacral nerves, which are part of the sacral plexus.

Blood Supply

The blood supply to the extensor coccygis is derived from branches of the internal iliac artery, which supplies blood to the pelvic region.

Function

The primary function of the extensor coccygis is to assist in the extension of the coccyx. It plays a role in the stabilization of the coccyx during movements of the pelvis and lower back. Although its function is not as prominent as other muscles in the region, it contributes to the overall stability and movement of the lower spine.

Clinical Significance

The extensor coccygis is not commonly associated with clinical conditions, but it can be involved in cases of coccydynia, which is pain in the coccyx area. Inflammation or injury to the coccyx can affect the extensor coccygis, leading to discomfort or pain during activities such as sitting or standing.

Also see

• Coccyx
• Sacrum
• Sacral plexus
• Coccydynia