Joints (anatomy).

In the musculoskeletal system, joints are structures that connect individual bones while allowing some type of movement and mechanical support. This skeletal articulation holds together distinct bones with strong, flexible soft tissues that enable movement on components of the skeleton by muscles on opposite sides of the joint that contract or relax. Joints occur between bones and other bones, bones and cartilage, bones and teeth, and cartilages. Based on their anatomical location, they are grouped between the joints of the trunk and the upper or lower extremity. They can be classified structurally, functionally, or biomechanically.