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 of the knee is about 4 times.
5.When playing ball, the weight of the knee is about 6 times.
6, squatting and kneeling, the weight of the knee is about 8 times.
For example: a person weighing 50kg, for each step, the knees have to bear about 200kg of weight. (50 * 4 times)
The human knee joint has the best condition for 15 years
Before the age of 15: The knee joint is in the developmental stage, and most of the growing pains in adolescence occur near the knee joint.
From 15 to 30 years old: 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.
Age 30-40: The patellofemoral cartilage is in an early stage of mild wear and tear, with a period of weakness and short-term knee pain lasting a few weeks to a few months, which some people do not even notice. Patellofemoral cartilage is a 3-5 mm thick layer of hyaline 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 onwards, the knee joint can no longer be used as you wish.
Age 40-50: 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, the 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 old: the knee joint will feel significant pain because the patellar cartilage has reached the end of its “useful life”, the cartilage is worn down and arthritis has developed. This is the time to conserve the use of the joint, reduce strenuous exercise, especially stairs and climbing, and use crutches if necessary to reduce the pressure on the knee joint.
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 together 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.
Daily care of knee pain.
1, do not walk too long, when the knee feels uncomfortable should 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, less wearing high heels.
8.Avoid trauma and overwork.
9, the choice of shoes is very important. A pair of shoes that fit can not only make you walk comfortably, but also reduce the impact and pressure on the knee during exercise.
Through the appropriate muscle strength, stability training can play a preventive health role for the knee joint
1, side lying exercises: lying on the left side, knees slightly bent, heels together. Head resting on the left arm, eyes looking straight ahead. The right hand holds a weight of about 1 to 2 kg, placed on the outside of the leg. Then tense the abdomen, tense the hips, lift the knee of the right leg as high as possible, hold the body still while lifting the leg, hold for a few seconds and put it down. Repeat the exercise 15 times, change legs.
2, leg lifting exercises: stand behind a solid bench or step, step on the right foot (heel do not overhang), and focus the weight on the right foot, the body is raised, the left foot toes contact the step, adhere to 1 to 5 seconds. Then lower the left foot and tap the ground. Repeat 8 to 10 times, change legs.
3, bridge exercise: lie flat on the ground, knees bent, feet apart, hip-width apart, arms on the sides. Slowly lift the hips and leave the ground smoothly. Then slowly put down. Repeat 15 times.
4, leg extension exercise: lie flat, knees bent, feet flat on the ground. Extend the left leg, set into the stretching band or towel, hands grasp the ends of the band. Use the strap to pull the leg to the chest, and then force the calf straight, hold for 10 to 30 seconds to exercise the calf muscles and hamstrings. Repeat the movement 3 to 5 times, then switch legs.