The pelvis contains several key ligaments that provide stability and support to the pelvic region. These ligaments connect the bones of the pelvis to each other and to the spine.
Key Pelvic Ligaments
Here's a breakdown of the major ligaments in the pelvis:
- Sacrotuberous Ligament: This strong ligament runs from the sacrum and coccyx to the ischial tuberosity (the "sit bone"). It helps to resist upward rotation of the sacrum.
- Sacrospinous Ligament: This ligament runs from the sacrum and coccyx to the ischial spine. It is shorter and deeper than the sacrotuberous ligament and also limits sacral rotation. Together with the sacrotuberous ligament, it forms the greater and lesser sciatic foramen.
- Iliolumbar Ligament: This strong ligament connects the transverse processes of the L4 and L5 vertebrae to the iliac crest. It stabilizes the lumbosacral junction and limits rotation and lateral flexion of the lumbar spine.
Additional Pelvic Ligaments
Besides the key ligaments mentioned above, the pelvis also contains several other ligaments that contribute to its stability:
- Anterior Sacroiliac Ligament: Located on the anterior aspect of the sacroiliac joint, this ligament provides support to the joint.
- Posterior Sacroiliac Ligament: This is a strong ligament complex located on the posterior aspect of the sacroiliac joint. It is the primary stabilizer of the sacroiliac joint and resists anterior and inferior movement of the sacrum.
- Interosseous Sacroiliac Ligament: This is the strongest of the sacroiliac ligaments and is located deep within the sacroiliac joint.
- Anterior Sacrococcygeal Ligament: This ligament connects the anterior aspect of the sacrum to the coccyx.
- Posterior Sacrococcygeal Ligament: This ligament connects the posterior aspect of the sacrum to the coccyx.
- Pectineal Ligament (Cooper's Ligament): Located along the pectineal line of the pubic bone, this ligament supports the superior pubic ramus.
Summary Table
| Ligament | Attachment Points | Function |
|---|---|---|
| Sacrotuberous | Sacrum & Coccyx to Ischial Tuberosity | Resists upward rotation of the sacrum |
| Sacrospinous | Sacrum & Coccyx to Ischial Spine | Limits sacral rotation; forms sciatic foramen |
| Iliolumbar | L4 & L5 Vertebrae to Iliac Crest | Stabilizes lumbosacral junction; limits rotation and lateral flexion |
| Anterior Sacroiliac | Anterior aspect of the Sacroiliac Joint | Supports the Sacroiliac Joint |
| Posterior Sacroiliac | Posterior aspect of the Sacroiliac Joint | Primary stabilizer of the Sacroiliac Joint; resists anterior and inferior movement of the sacrum |
| Interosseous Sacroiliac | Deep within Sacroiliac Joint | Strongest Sacroiliac ligament |
| Anterior Sacrococcygeal | Anterior Sacrum to Coccyx | Connects sacrum to coccyx |
| Posterior Sacrococcygeal | Posterior Sacrum to Coccyx | Connects sacrum to coccyx |
| Pectineal (Cooper's) | Pectineal Line of Pubic Bone | Supports the superior pubic ramus |
These ligaments work together to provide a strong and stable foundation for the body, allowing for efficient movement and weight-bearing.
