Our knee joint is the largest joint in the human body. When we walk on the ground, go upstairs and downstairs and squat, it is mainly the knee joint that plays a role. The flexion and extension of the knee joint is the key factor to complete the above actions. Each of us has pain symptoms in our knee earlier than in other joints. At the age of 50, the knee joint is more or less painful, and even some people have knee pain before the age of 50. It just caters to the old saying: "old legs grow old first". Why is such an important joint more prone to aging? If we know the reasons, we can maintain the knee joint and prevent the occurrence of aging arthritis. Truth one More exercise requires control Every movement of human beings in the standing position is inseparable from the knee joint. Walking, running, jumping, squatting, the role of knee joint is essential. Ordinary normal people need about 10000 steps a day, not counting the steps of exercise. Therefore, under the condition of normal use, the knee joint has been overworked and damaged. If there is additional exercise, it can strengthen the body within a certain range. Once it is excessive, it will accelerate the wear and aging of joints. Every day, both knees should be flexed and extended at least 10000 times under the condition of weight-bearing. In addition to the knee flexion and extension activities when sitting and lying in bed, the number of knee flexion and extension should be about 20000 times. The knee is so hard, so how can people who love sports, those who want to exercise their physique, those who want to exercise weight loss, and those who need exercise to control blood sugar, can control the amount of exercise, not only to achieve the purpose of exercise, but also not to accelerate the aging of the knee joint? The principle of conservation program is that it varies from person to person and from time to time; Gradually increase the amount, enough is enough. Each person is born with different physique, bone, joints, tendons, muscles and other sports organizations, as well as the strength of the cardiopulmonary system. Naturally, the amount of exercise that can be tolerated is different, so everyone can not be measured by the same sports standard. How to master the amount of exercise? It mainly depends on everyone's own feelings. Every kind of exercise can be carried out. There is no discomfort in the body during the exercise. After the exercise, there is no pain in all parts of the body, and there can be a sense of mild fatigue. The next day, there is no feeling of excessive fatigue and no relief from rest. At this time, the amount of exercise is appropriate. With the enhancement of physique, the amount of exercise can gradually increase. After the increase, the faster relief of pain and fatigue is the amount of exercise we can bear that is conducive to health. Truth two Great burden, control your weight and reduce its burden Among the four major joints of shoulder, elbow, hip and knee with the largest range of human activity, the knee joint is at a low level, so the weight borne by the knee joint is the most among the four major joints. The shoulder joint and elbow joint are located in the upper limb. In addition to the weight of the upper limb, they hardly bear the weight, so the degeneration speed of the upper limb joint is relatively late, and the wear degree of articular cartilage is relatively light. But the knee joint is different from it. It is a typical weight-bearing joint. It can be said that weight-bearing is the main task of the knee joint. In particular, we should not only bear weight, but also move. For example, when squatting, the quadriceps femoris contracts strongly, pulls the patellar tendon, and then pressurizes the patella, resulting in the joint surface between the patella and the femur bearing much more load than usual. Similarly, when we go up and down the stairs, the articular cartilage between the patella and femur is also under great pressure. When going down the stairs, the articular cartilage between femur and tibia also bears the impact of falling potential energy of the body, that is, weight plus impact, so it will cause greater damage to the joints when going down the stairs. Since the position of the maintenance plan determines the weight of the knee joint, what we can do is to control our weight. Fat people, that is, people with heavy weight, will inevitably increase the load on their joints. Conversely, to reduce the load on the knee, you must reduce weight. If you keep your weight within the normal range, there will be no additional load on the knee joint, and the aging speed will slow down. However, it should be noted that for people with normal weight, there is no need to lose weight. Because the lighter the weight, the better. Too light weight will also affect the strength and stability of joints. For example, people who are too light are prone to osteoporosis, so the joints composed of bones must be damaged in strength. Specific to the knee joint, osteoporosis will lead to the decrease of subchondral bone strength of the medial tibial plateau. For example, if the foundation of the house is not firm, the stress on the cartilage on the surface of subchondral bone will be uneven, resulting in early cartilage degradation. Truth three Complex structure to avoid trauma affecting joint firmness The structure of knee joint is complex. It is composed of three bone structures: distal femur, proximal tibia and patella. The surface of bone structure is covered with hyaline cartilage to reduce friction and buffer stress, forming patellofemoral joint and femoral tibial joint. There is a meniscus between tibia and femur, which is a kind of fibrocartilage pad. Its function is to increase the contact area between tibia and femur, stabilize the joint, disperse stress and reduce impact force; There are also anterior cruciate ligament and posterior cruciate ligament, which cooperate subtly to maintain the stability of knee joint during flexion and extension. If these two ligaments are damaged or even broken, it will lead to instability of knee joint and accelerate joint wear and aging. The distal and proximal ends of the patella connect the patellar tendon and quadriceps femoris tendon respectively, and there are medial and lateral collateral ligaments on both sides of the knee joint. One of the above structures is damaged or the degenerative strength is not enough, which will affect the stability of the knee joint and accelerate the aging of the joint. The maintenance plan cannot be changed. What we can do is to avoid knee trauma as much as possible. Once the injury is difficult to repair due to its complex structure, it is impossible to repair completely, which will inevitably lead to the decline of the stability and firmness of the joint and the acceleration of joint aging. If you are injured, you need to rest fully and try to recover the joints to the greatest extent, otherwise it will be more difficult to deal with the residual symptoms. Truth four Keep warm and don't catch cold Using "skin and bone" to describe the state of the knee joint can not be more vivid. There is no muscle protection around it. Because there are no muscles around the knee joint and the thickness of structures such as skin ligament and joint capsule is small, the knee joint is easy to catch cold. Vasoconstriction after cold will inevitably lead to the decrease of blood flow, resulting in insufficient support of joints and surrounding structures. After joint wear, it can not be repaired in time, which will lead to easy wear of articular cartilage, edema and inflammation of synovium. Over time, irreversible damage to the knee joint is formed. Some people say that Europeans and Americans, Russians and Japanese have no habit of wearing autumn pants, and their knees are not so bad? In fact, there are some disputes about this horizontal comparison. The racial constitution of Europeans, Americans and Russians is quite different from ours. They are more tolerant of cold; The Japanese, who have been barefooted at all times since birth, may be able to adapt to the cold early, and their knee blood vessels are also adapted to work in cold conditions without cold contraction. Maintenance scheme our people's knee joints can't withstand the cold, so we must pay attention to keeping warm. In particular, with the aging of the joints, we need to keep warm. This is actually the easiest link in joint maintenance. Truth five Articular cartilage can not regenerate and repair in time The articular cartilage in the knee joint bears great pressure. Impact, friction, instability, synovitis and poor nutrition will affect the integrity of the cartilage. Over time, the cartilage will be chapped, stripped and missing, and once the cartilage is damaged to a certain extent, it will not regenerate. The best way of maintenance program is not to damage articular cartilage or strengthen articular cartilage. At present, there are drugs to supplement articular cartilage, such as glucosamine, chondroitin sulfate and keratin sulfate. It can repair articular cartilage when it is still healthy or slightly damaged. This repair effect is limited and varies from person to person. (outlook new era)