Osteoarthritis of the knee, also known as degenerative knee disease or age-related knee osteoarthritis, is a common and frequent disease of the middle-aged and elderly, and is a natural phenomenon and an inevitable result of aging and decades of joint movement in humans. The incidence of the disease gradually increases with age, and the incidence increases significantly after the age of 50. The incidence in women is about four to five times higher than that in men. Inside the knee joint, there is articular cartilage that acts as a cushion on the surface of both the thigh and calf bones. As this cartilage wears away, patients experience pain in the knee joint when walking or going up and down stairs. Among the joints of the human body, the knee joint has to support the weight of the whole body, but also has to stand, squat, jump, run, walk, etc. Therefore, the knee joint is very active and most prone to knee joint wear and tear, so osteoarthritis of the knee joint is the most common. The main factors that trigger the onset of osteoarthritis of the knee are excessive joint activity, walking too far or walking up and down hills and stairs too often, and poor joint posture, lack of knee movement due to standing or sitting for too long. The main symptoms of osteoarthritis of the knee are: 1. Joint pain: initially intermittent pain, pain when walking up and down stairs or pain after prolonged exercise, and in severe cases pain with every step, even at rest. 2. Restricted joint movement: As the cartilage in the joints wears down, the flexibility of the joints decreases, and when standing and walking, you need to move the joints a few times before you can take a step. 3. Joint instability: Usually, the wear and tear of the knee cartilage occurs first in the medial cartilage, which leads to unstable knee joints and the appearance of “O” shaped legs. Most patients are afraid to move their legs and feet because the pain in the knee joint increases when they move, which leads to atrophy of the muscles in the lower extremities, so the stability of the knee joint decreases and the load on the knee joint increases when they move, and the pain only increases. If you are already experiencing some of these symptoms, this means you have osteoarthritis of the knee. When the symptoms are mild, the development of the disease can often be slowed down by the following methods: 1. Avoid strenuous, prolonged exercise: Often, some older people suffer from knee osteoarthritis after strenuous exercise or prolonged walking, making the symptoms worse and not relieved for a long time. 2, reduce weight: can reduce the load on the knee joint, to avoid aggravation of the disease. 3, functional exercise: the principle of functional exercise of the knee joint is based on active non-weight-bearing activities, such as straight leg raising exercises, which enhance muscle strength and maintain the stability of the joint. 4. Reduce sports such as running and jumping, stairs and climbing: switch to sports such as swimming or cycling. 5. Use rigid knee pads: to protect the stability of the knee joint.