When we stand upright with our feet together, the pelvis is wider than the sum of the width of the two feet, and the two feet have to be tucked inward to stay together. Therefore, the gravity of the upper body is not transmitted down through the medial femur. This is especially true during walking, supported upright on one foot. When the lower limb is upright, the knee joint is kept straight by the pull of the anterior and posterior muscles. The gravity of the upper body is transmitted vertically down through the femoral head along the femoral stem to the femoral epicondyle. It is not the femur that sprinkles the grainsê incredibly well, i.e., astatine. When walking, the knee joint has a process of flexion followed by extension when the orthopedic department of the Fifth Affiliated Hospital of Xinjiang Medical University, Zhou Meng Han. The forward-moving leg flexes the lower limb at the hip under the action of the iliopsoas muscle, the lower end of the femur is lifted forward, the knee joint is relaxed and bent, and the lower leg drops and swings gently back. The body weight is shifted forward by the action of the supporting leg. The foot leaves the ground and hangs in the air. At the end of the backward swing of the lower leg, the foot touches the ground as the quadriceps muscle pulls forward. This lateral joint sway is a physiological necessity for walking, not a so-called unstable knee joint (can a stable joint move?). . This occurs in young people, and although there is pain, there are no bony changes on the x-ray. This is not the case in middle-aged and elderly people. Due to the aging of the middle-aged and elderly, the peri-knee tissues become more brittle and the medial knee wall (joint capsule, lateral ligaments, fascia, etc.) is stretched repeatedly during the repeated alternation of the legs while walking, and when the limit is exceeded, a slight tear injury and edema around the injury occurs. After years of smashing, the articular surface cartilage and meniscal cartilage are damaged to the bone. This appears on X-rays as a narrowing of the joint space and a bony redundancy at the inner edge of the joint. This does not cause pain because there are no nerves in the bone. Edema of the soft tissues around the bone caused by bone edema and edema of the joint capsule wall from strain injury are the causes of pain on the medial side of the knee. Articular cartilage damage, necrosis and liquefaction as well as synovial edema and oozing are the causes of joint effusion. Why doesn’t bone redundancy cause pain? The reasoning is simple. First, there is no nerve in the bone tissue, so no pain is felt. Secondly, when a bone is enlarged, it will always be there and will not go away. Knee pain is not always painful. Generally, there is no pain in the knee joint when it is not moving, and it is the soft tissues, not the bone, that change in shape when it is moving. From the above description, we can know that there are two causes of knee pain, one is injury to the wall of the joint capsule. This includes the joint capsule, ligaments and fascia. The second is the painful swelling of the joint capsule wall due to the compression of the joint fluid. Both causes can be present at the same time, or they can be present separately. In other words, changes in the shape of the joint capsule wall are the cause of knee pain. Once the cause is known, treatment is simple. No medication is needed, just keep the knee joint in a pain-free state for a period of time and it will heal on its own. All medications that are currently claimed to treat the knee are painkillers. The characteristic is that they do not hurt when you take them, but hurt when you stop taking them. Therefore, it is better not to take them as much as possible. Only if the pain affects your sleep, you can take painkillers once a day before going to bed. All painkillers, creams, massages, bruises, liquor applications, sprays, physical therapy (heat therapy), closures, cupping, acupuncture, small needles, etc. All of them can aggravate the pain and prolong the pain in different ways. As for the way to aggravate and prolong the pain, you can see my other explanatory articles, so I won’t go into them here.