Obstetric and Gynecological Nursing - The Carter Center

sacrum is concave and is referred to as the hallow of the
sacrum.
C. The coccyx: - is avestigial tail. It consists of four fused
vertebrae forming a small triangular bone.
Pelvic Joints
There are four pelvic joints
- One Symphysis pubis
- Two Sacro illiac joint
- One Sacro coccygeal joint
- The symphysis pubis is a cartilgeous joint formed by
junction of the two pubic bones along the midline.
• The sacro iliac joints are the strongest joints in the
body.
- The sacro coccygeal joint is formed where the base of the
coccyx articulates with the tip of the sacrum.
In non pregnant state there is very little movement in these
joints but during pregnancy endocrine activity causes the
ligaments to soften which allows the joints to give & provide
more room for the fetal head as it passes through the pelvis.
Pelvic ligaments
Each of the pelvic joints is held together by ligaments
- Interpubic ligaments at the symphysis pubis (1)
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