Osteoarthritis, also known as degenerative joint disease, is the most common form of arthritis, and it generally occurs as a result of wear and tear. Signs and symptoms include pain, tenderness, warmth, swelling and joint stiffness. Osteoarthritis involves the progressive erosion of the soft tissue (cartilage) that protects the surface of the bones, and the formation of bone spurs (osteophytes).
Osteoarthritis can cause inflammation of the bones, muscles, ligaments, cartilage, and tendons surrounding the affected joints. It also has the potential to affect other internal body areas. Osteoarthritis can result in weakness of muscles thereby resulting in loss of balance.
American Physical Therapy Association Guide to Osteoarthritis