As we age, our knees take a beating. We use them to walk, stand and climb stairs, and they are used when we get up from a sitting or lying position. When our knees hurt, everyday tasks are harder to do. Chronic knee pain is often a form of arthritis that occurs when the cushioning cartilage protecting the knee joints starts to wear down. As more cartilage wears away, the space between the bones narrows resulting in bone rubbing against bone. Knee arthritis is a deteriorating condition, and in addition to pain, can cause deformities such as knock knees or bowlegs. Experts explain there are three forms of arthritis that affect the knee. The first is a degenerative joint disease called osteoarthritis; another is the autoimmune disease known as rheumatoid arthritis; and finally post-traumatic knee arthritis that happens with a history of injury or trauma. Factors increasing your risk for knee arthritis include the wear and tear that comes from age, being overweight, heredity, gender, and...