The symphysis pubis or pubic symphysis is part of a human's pelvic girdle area. It connects the right and left sides of the pubic bone together while allowing for a restricted amount of movement to occur. This joint is permanent but changes in pregnancy. The symphysis pubis acts in conjunction with the sacral joint (also in the pelvic region) and local muscles and ligaments to allow for a normal range of motion.
A symphysis pubis is a cartilaginous joint, which is made up of bones connected together by cartilage, a specific tissue type for connective purposes. Cartilaginous joints are also known as amphiarthroses. They are joints that can move slightly but not a lot. A symphysis pubis uses a type of cartilage called fibrocartilage. It contains cells known as chondrocytes mixed with a strong and flexible tissue made from sugars, protein and collagen. The fibrocartilage allows the pubic symphysis to extend and contract.
The cartilaginous joints are divided into those joints that use hyaline cartilage (a second type of cartilage) and those that use fibrocartilage. The fibrocartilage joints are called symphyses. Along with where it is located in the body, this is where the pubic symphysis gets its name.
A symphysis is a joint where the bones joined together are covered in hyaline cartilage and a fibrocartilage disk separates these bones from each other, which allows them to work in conjunction during movement. The fibrocartilage disk is not covered with another material like some other joints but attaches directly to the tissues around it.
The symphysis pubis acts to absorb shock to the body when a person walks around. This shock absorbing capability is due to the flexibility and toughness of the fibrocartilage of the joint. The movement that occurs is a gliding motion, where each side of the pubic bone can move up or down relative to the other. The stretchy cartilage also accommodates the separation and closing together of the bones. The pubic symphysis also has a role to play in pregnancy to accommodate the baby's delivery.