Rheumatology is concerned with diseases of the joints, bones and soft tissues. The only common denominator of these diseases is impairment of the functional capacity of the locomotor apparatus as a result of pain or stiffness. This involves in particular diseases of the skeleton (osteoporosis, osteomalacia), degenerative diseases of the joints (osteoarthritis, diseases of the back ), inflammation (rheumatoid arthritis, ankylosing spondylitis, vasculitis), periarticular diseases (inflammation of the tendon sheath, periarthritis) and muscle diseases (sprains, myositis).