Osteoarthritis is one of the most common forms of arthritis. It is also the most common disease in older adults. In North America, 70% of people with osteoarthritis are older than 65 years old. And 30% of women over the age of 65 have varying degrees of osteoarthritis. In the United States, it is the leading chronic disorder that causes patients to waste away. The incidence is high, with 8 million people affected in the United Kingdom and 27 million in the United States, and the number is increasing. People with a history of joint trauma, obesity, and long periods of seated work are more likely to develop osteoarthritis. It usually affects weight-bearing joints, such as the lumbar spine, hip and knee joints. Primary hip osteoarthritis is less common in China, while primary knee osteoarthritis is the most common, so osteoarthritis generally refers to knee osteoarthritis. The dangers of osteoarthritis include: severe deformation of the joint, inversion or valgus deformity, flexion and contracture, limited flexion and extension, locking and unstable walking, falls, and even inability to walk. The pain affects walking and increases obesity, increases the burden on the heart and lungs, and decreases general health. It also causes patients to become psychologically depressed because of concerns about increasing obesity. Prevention of osteoarthritis includes: 1. Weight loss: Weight loss is a very effective prevention method, especially for obese patients. There is clear evidence that a patient’s weight is positively correlated with the severity of osteoarthritis. Weight loss not only reduces the force on the tibiofemoral joint of the knee, but also reduces the force on the patellofemoral joint, preventing the onset of the disease, reducing symptoms, and slowing the progression of the disease. 2, appropriate exercise: for the prevention of osteoarthritis is also very important, from the perspective of osteoarthritis prevention, swimming is the best exercise, both to achieve the required amount of exercise, but also to avoid overloading the knee joint, increasing the wear and tear of joint cartilage. The movement of climbing, going up and down the stairs excessively, playing soccer, playing tai chi, etc. in a flexed knee state where the knee joint is overstressed is not a very suitable exercise. 3, exercise to increase muscle strength: such as increasing the quadriceps muscle strength exercise, can increase the stability of the knee joint, reduce the abnormal force on the knee joint, to avoid or delay the development of osteoarthritis. But this exercise should not make the muscles too fatigued. 4. Increase joint mobility: Exercise is also vital to the prevention of osteoarthritis and can be a way to reduce stiffness, increase joint mobility, and prevent contractures of soft tissues. Other things including education for people with osteoarthritis, etc. can also play an important role in preventing the onset and development of osteoarthritis.