Joints connect bones and allow movement. There are 230 joints in the body which are classified structurally as fibrous, cartilaginous, or synovial joints depending on how the bones connect, and functionally as synarthrosis, amphiarthrosis, or diarthrosis based on movement. Common joint disorders include sprains, dislocations, bursitis, tendonitis, and various forms of arthritis such as osteoarthritis and rheumatoid arthritis.