Slightly movable joints are also known as cartilaginous joints or amphiarthrosis joints. These types of joints are formed by bones that are connected by cartilage. The joints are only slightly movable and cannot rotate or move freely.
Joints can be classified on the basis of structure or function. Structural classification deals with the manner in which the bones are connected, while functional classification has to do with the range of motion that a joint allows.
Amphiarthrosis is a functional joint class. The other two are synarthrosis, which allows for restricted or no mobility, and diarthrosis, which permits free mobility.
Slightly movable joints form when two bones come together with a small piece of cartilage in between them. Examples of slightly movable joints include the joints between each vertebrae in the spine. The vertebrae surround intervertebral discs, which are cartilage formations. Other examples of slightly movable joints include the symphysis pubis and the sacroiliac joints, which are both located in the pelvis. In the human body there are also immovable joints and freely movable joints.