The knee, the largest and most complex joint in the body, is a hinge joint, and it is one of the few joints in our body that can only move in one direction. The knee is also the largest weight-bearing joint in the human body, and the average knee joint in a normal person can support 35 kg of weight. The more weight you carry, the greater the chance of wear and tear on the joint cartilage, and the tendons are prone to injury and faster degeneration of the knee joint.
I. The weight-bearing multiples of the knee are as follows.
1. When lying down, the weight bearing of the knee is almost 0.
2. When standing up and walking, the weight on the knee is about 1 to 2 times.
3. When walking up and down a slope or up and down a staircase, the weight on the knee is about 3 to 4 times.
4. When running, the weight on the knee is about 4 times.
5. When playing ball, the weight of the knee is about 6 times.
6. When squatting and kneeling, the weight of the knee is about 8 times.
For example, a person weighing 50kg has to bear about 200kg of weight on his knees for each step. (50 * 4 times)
Second, the human knee joint quality has the best condition for 15 years.
Before 15 years old.
The knee joint is in the developmental stage, and most of the growing pains in adolescence occur near the knee joint.
From the age of 15 to 30.
The knee joint is in “perfect condition” and works tirelessly. As long as the knee joint tissue is not damaged, it is basically not felt.
Ages 30-40.
The patellofemoral cartilage develops early and mild wear and tear, and a period of weakness occurs, with short-term knee pain that lasts a few weeks to a few months and is not even noticeable in some people. Patellofemoral cartilage is a 3 to 5 mm thick layer of clear cartilage in the human knee joint that cushions the knee joint from the impact of movement.
However, because the patellar cartilage has no nerve distribution, it will only sound an “early warning signal” once during the vulnerable period before the full layer wears out, and strenuous exercise should be avoided during this period. From this time on, the knee joint can no longer be used as you wish.
From 40 to 50 years old.
After walking long distances, the inside of the knee joint tends to become sore and painful, which is relieved by rubbing it with your hands. In the knee joint, the meniscus serves to cushion vibrations and maintain stability. Since 60% of the body weight is supported by the medial side of the knee joint, degeneration of the medial meniscus occurs earlier. Because of the nerve distribution in the meniscus, people can feel soreness and pain during the degeneration process. This phenomenon is a reminder that it is time to start taking care of your joints.
Over 50 years of age.
This is because the patellar cartilage has reached the end of its “useful life” and the whole layer of cartilage has become sore.
Third, the causes of knee pain in middle-aged and elderly people.
After middle age, the tendons and ligaments of the knee joint begin to undergo degenerative changes, the synovial fluid secretion in the joint cavity decreases, the bone surface of the joint rubs for a long time to form bone wear, and the tissues around the joint are prone to fibrous adhesions due to inflammation, so the elderly often feel stiffness in the knee joint.
This is why the elderly often feel stiffness in their knee joints. When they move, they will make a “clicking” sound or frictional sound, and when they are cold or overly active, they will experience pain, swelling, and fluid accumulation in the joint cavity, and in severe cases, they will have deformed joints and become disabled. Specifically, the causes of knee pain in the elderly are as follows.
1, chronic synovitis: chronic pain and swelling in the knee joint. Synovial effusion and synovial hypertrophy can be seen on physical examination.
2. Patellar deviation: the knee joint is sore and weak after activity, improves after rest, and is painful when semi-squatting.
3, free body in the knee joint: the patient’s leg is weak or has a feeling of joint jamming, and there is a friction sound under the patella.
4, prepatellar bursitis: there is a history of trauma, causing prepatellar pain, and localized pressure pain on physical examination.
5, osteoarthrosis: joint pain is obvious after sitting or squatting for a long time, when standing up or going up or down stairs, and relieved after rest.
6, pseudogout: more male patients, preferably in the knee joint. X-rays show calcification of meniscus and articular cartilage surface.
7, femoral head necrosis: hip lesions with knee pain symptoms.
Fourth, the pain of different parts of the knee joint.
1, pain in the lateral iliotibial band of the knee.
2, around the knee before the knee pain, also called patellofemoral joint pain.
3, pain above the knee, probably quadriceps tendonitis.
4, pain above the kneecap or on the inner side of the upper tibia, may be bursitis.
V. Daily health care for sore knees.
1, do not walk for too long, when the knee feels uncomfortable should be immediately rest.
2, do not do a large amount of exercise, such as running, high jump, long jump.
3, avoid half squat, full squat or kneeling position. Such as squatting horse stance.
4, do not do the knee joint half flexion rotation action, to prevent half plate injury.
5, maintain the ideal weight to reduce the burden on the knee.
6, pay attention to the warmth of the knee, you can wear long pants, knee pads to protect the knee.
7.Less heavy lifting and less wearing of high heels.