Osteoarthritis is a degenerative disease caused by ageing, obesity, strain, trauma, congenital abnormalities of joints, joint deformities and many other factors, such as degenerative damage to joint cartilage, reactive hyperplasia of joint edges and subchondral bone, also known as osteoarthrosis, degenerative arthritis, age-related arthritis, hypertrophic arthritis, etc. The clinical manifestations are slowly developing joint pain, pressure pain, stiffness, joint swelling, limitation of movement and joint deformity. Etiology: 1. Loss of collagen components: As we age, the knee joint undergoes degenerative changes. We all know that collagen occupies a large portion of both bone and joint, with collagen accounting for 1/3 of the bone and 59% of the cartilage in the joint. After the age of 35, collagen and calcium are gradually lost, which can easily cause osteoarthritis, osteoporosis and other bone and joint diseases. 2, obesity: epidemiological studies have found that obesity can induce the occurrence of osteoarthritis of the knee joint. The stress and direction of the knee joint depends on the force line of the limb, body shape, muscle strength and its interaction. Obese people, especially women, the incidence of osteoarthritis of the knee is four times that of normal weight women. 3, long-term joint weight damage: many people in the elderly like to climb two or three times a week, or up and down the stairs three times a day, squatting for 10 minutes, jogging for half an hour and other sports, in fact, these exercises, if excessive, is very damaging to the joints. For example, when climbing stairs, the joints have to bear three to four times their weight, which will increase the burden and damage to the knee joint, the curvature of the knee joint increases, the pressure between the patella and femur also increases, and along with the increased wear and tear between the bone and the bone, resulting in knee pain. So when you go down the mountain, you’d better take the cable car down, and when you go down the stairs, it’s better to take the elevator.