Knee osteoarthritis is a non-inflammatory degenerative change in the cartilage of the joint caused by old age or other causes, with the formation of bone fragments at the edges of the joint, and is commonly known by many names, such as osteoarthrosis, degenerative joint disease, age-related arthritis, hypertrophic arthritis, deformational arthritis, etc. In outpatient clinics, more and more patients are coming to the doctor for knee pain, mainly middle-aged and elderly women. “Do I have rheumatoid arthritis?” “Will my knee pain become rheumatoid arthritis?” “When I move my knee joint, why does it make a clicking, clicking sound?” …… Although the questions asked were different, it was evident that everyone was anxious about their knee pain. Most of these patients had similar symptoms: sore knee joints, inflexible activities; stiff and painful joints after waking up in the morning or after sitting for a long time, and a little activity to walk; painful joints after standing or walking for too long and needing to sit down to rest; struggling to go up steps and having weak legs to go down steps; difficulty squatting and sometimes needing support to stand up; “clicking, clicking” when extending and flexing the knee joint; “clicking, clicking” when moving the knee joint. “The pain and swelling of the knee joint may increase with excessive activity. If an X-ray of the knee is done, the report often shows “narrowing of the bone space and formation of bone fragments (or osteophytes)”, which is commonly referred to as “long bone spurs”. Combining the clinical findings with the x-ray findings, the doctor will conclude that the knee is “osteoarthritic”. Osteoarthritis of the knee is a degenerative change in the cartilage of the joint resulting in cartilage loss and destruction, accompanied by periarticular osteophyte reaction, also known as osteoarthrosis, degenerative arthritis, proliferative arthritis, hypertrophic arthritis, and age-related arthritis. After the age of 45, the ovarian function of women decreases and the level of estrogen decreases, which weakens the metabolism of joint cartilage and makes it prone to degenerative changes. Long-term chronic joint strain and increased knee joint load is another cause of the disease, and occupations that require frequent standing and walking, such as weavers and salespeople, are mostly women, plus most middle-aged women are fat, especially after menopause. Therefore, the prevalence of osteoarthritis of the knee increases with age, with more women than men and an earlier age of onset than men. In recent years, the incidence of knee osteoarthritis has increased among women who are physically active after retirement, which may be related to excessive knee activity. Some people who have osteoarthritis of the knee worry that they will be disabled in the future and think that they must exercise to keep their joints functional; some people think that they have the disease because they are older and less active, so as long as they are more active, they can reduce their pain and the more they are active. So, they repeatedly flex and extend the knee joint with pain, rub the patella, move the knee joint, and even walk for 1-2 hours or go hiking or running. Others use fitness equipment for the purpose of strengthening the knee joint. In fact, this is incorrect because excessive activity increases the wear and tear on joint cartilage and can induce synovial congestion causing joint effusion. Going up and down steps and running increases the stress on the joints, and this exercise can only make joint pain worse. Even in patients who do not have joint pain but only have “bone spurs” found on x-rays, joint pain and even joint effusion can occur after a period of time. Therefore, osteoarthritis of the knee requires rest, but of course not to the extreme, because complete rest without movement will result in muscle atrophy due to disuse. You should exercise properly to maintain the mobility and muscle strength of the joints. The right thing to do: get more sunlight, pay attention to cold and dampness, keep warm and give the knee joint a good rest. After the pain is relieved, walk slowly on flat ground once or twice a day for 20-30 minutes each time. Try to reduce weight-bearing movements on the knee joint such as going up and down steps and running to avoid and reduce the wear and tear of joint cartilage. Don’t stay in one position for a long time, and don’t do exercises such as repeatedly flexing and extending the knee joint, rubbing the patella and shaking the knee joint blindly. Exercise the quadriceps to make them strong and powerful to reduce knee pain. The specific exercise method suitable for middle-aged and elderly people is: sitting or supine position, straighten the knee joint, tense the thigh muscle, foot to the head dorsiflexion, while tensing the calf muscle, each time adhere to three or four seconds, do 10 times per minute, do three or four minutes in a row. You can do it three or four times a day. Life guidance for patients with knee osteoarthritis is very important. Patients should pay attention to rest, combine work and rest, move within the scope of their condition, do not overload, get cold and damp, avoid being sedentary, especially not to bend the knee less than 90° for a long time. Obese patients should lose weight to reduce weight bearing; pay attention to functional exercises, mainly active non-weight bearing activities, first for muscle strengthening exercises, then gradually practice to increase joint activities, not suitable for squatting exercises, avoid squatting toilets, change to sitting toilets.