This exercise is good for your knees. It is simple and effective. You can do it at home! Try it now

October 12 is "International Arthritis Day". The purpose of establishing this "holiday" is mainly to call on the whole society to recognize the disease of arthritis, carry out early prevention and treatment, and improve people's quality of life.

When it comes to arthritis, we may naturally think of some old sayings, such as "It takes a hundred days to heal a broken bone" and "The legs age first when people get old". Among them, arthritis of the knee joint is the most common. Today, we will take the knee joint as the starting point to talk in detail about how arthritis comes about and how to prevent arthritis.

How does the knee joint work?

The knee joint is the largest joint in our body and is composed mainly of our thigh bone (femur), shin bone (tibia), and patella (called the "patella" in some places).

The picture comes from the Internet

The main movements of the knee joint are flexion and extension, with some minor sliding and rotation during flexion and extension. There are also many ligaments distributed inside and around the knee joint, such as the anterior cruciate ligament and the posterior cruciate ligament, which prevent excessive anterior and posterior displacement of the tibia during knee movement.

There is a medial collateral ligament on the inside of the knee joint and a lateral collateral ligament on the outside. They are mainly responsible for protecting the tibia from left-right displacement, that is, the inward and outward rotation of the knee joint. In the gap between the joints, there is also a structure called the meniscus, which is named after its appearance that resembles a half moon. The meniscus mainly plays a role in deepening the joint socket and improving stability.

The surface of the joint is covered with a layer of white cartilage. With the cooperation of synovial fluid, the friction between the cartilage is very low, so we can move smoothly. As a movable structure on the front of the knee joint, the patella can increase the torque. Through the patella, when the quadriceps of our thigh exerts force, it can better apply force to the tibia, thereby completing the kicking action.

Many people say that the legs age first. This is because the knee joint is used very frequently, and is subjected to the most force whether walking or going up and down stairs.

Therefore, most people will experience knee discomfort after a certain age due to joint wear and tear. This kind of wear and tear of joints caused by long-term use is called osteoarthritis. The core problem of osteoarthritis is the damage to the cartilage on the surface of the joint.

What happens if cartilage is damaged?

We generally divide human cartilage into three categories:

1. Fibrocartilage, such as the meniscus mentioned above;

2. Elastic cartilage, such as the cartilage inside our nose and ears;

3. Hyaline cartilage, which is the most precious cartilage covering the surface of our joints.

Even with advanced technology today, we still cannot regenerate hyaline cartilage on the surface of joints. There are no blood vessels inside hyaline cartilage, and its metabolism mainly depends on synovial fluid. Therefore, when hyaline cartilage is injured or worn, it is difficult for us to restore and repair it. So in theory, after adulthood, hyaline cartilage is in a process of continuous wear and tear.

As we age, cartilage will gradually degenerate. For example, the texture of cartilage in some parts may change from tough to soft, and some parts may become thinner, cracked, rough, or even peel off. At this time, our body will have a series of reactions, such as joint pain, tenderness, frequent swelling, etc.

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If severe wear and tear continues to occur, it may also lead to limited range of motion, joint deformity, etc. The above series of joint symptoms caused by cartilage wear are defined as osteoarthritis.

Is there any way to prevent it?

For young people, there is no need to be overly nervous, because osteoarthritis of the knee generally occurs only after accumulation of symptoms at a certain age.

Of course, the onset of osteoarthritis is also a gradual and slow process. If you want to avoid the occurrence of osteoarthritis, I hope you can pay attention to the following points.

1

Maintain a healthy exercise habit

In fact, the human body is also a very delicate "mechanical structure", so if this "mechanical structure" is not used for a long time, it will definitely face the situation of "rust". Reasonable exercise habits can keep the joints in the best condition. Of course, you can't exercise too much, everyone's limit is different, you must fully understand your own ability, and reasonable exercise can make the joints last longer.

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2

Weight control

You should know that when we go up and down stairs, run, jump and other exercises, the knee joints often produce pressure several times that of our own body weight, so if the weight is not controlled, it will inevitably affect the life of the knee joints. In addition to a reasonable diet, regular exercise mentioned above is also the most effective way to control weight. But this should be done in advance. Many people find that they are already overweight and then have joint pain. If they want to make up for it and do a surprise exercise to lose weight, it will often only cause more damage to the joints.

3

Maintain muscle strength around the knee

There are many muscles around the knee joint, and the most important muscle for the knee joint is the quadriceps. The quadriceps is mainly composed of the medial head, lateral head, rectus femoris and vastus intermedius. The kicking action can be completed by contracting the quadriceps. Almost all human movements are inseparable from the participation of the quadriceps. Strong quadriceps can fully improve the stability of the knee joint, thereby avoiding the occurrence of additional adverse pressure on the knee joint. As people age, their muscle content will gradually decrease. If we can intervene in muscle strength training in advance to slow down muscle loss, then the life of our knee joints will be extended accordingly. Finally, I recommend a very simple and effective method of training the quadriceps of the knee joint, which you can do at home or in the office:

Sit on the bed or a sturdy large table, let your knees hang naturally, then slowly kick one leg forward so that your thigh and calf are parallel to the ground.

Key points: When doing this movement, think about straightening your knee joint instead of lifting your leg, otherwise the contraction will come more from the rectus femoris and iliopsoas muscles, which may cause discomfort in the hip joint.

√ Correct posture:

Source: Photographed by the author

×Wrong posture (thighs slightly lifted off the bed):

Source: Photographed by the author

When you reach the end of the kick, hold for 30 seconds to 1 minute. You will feel the muscles above the knee joint becoming sore and swollen. When you feel fatigued to the limit, you can slowly lower it. Some patients who have had knee pain before may experience more pain during the fall. In this case, you can use the other leg to support the fall to avoid pain. Generally, after 2 to 3 weeks of persistence, this pain or discomfort will gradually disappear.

It is generally recommended to hold this action for about 1 minute each time, 6 to 8 sets a day. As time goes by, muscles begin to grow, and many people no longer feel tired after about 1 minute. In this case, you can gradually extend the leg lifting time or add small sandbags to your ankles to increase resistance.

As shown in the figure below↓↓↓

Source: Photographed by the author

Most of us may encounter osteoarthritis of the knee joint, but if our muscle strength can be guaranteed, the impact of osteoarthritis on us will be greatly reduced. In my clinical work, I found a rule that may be a bit counterintuitive, that is, the less active people are, the more likely they are to develop osteoarthritis, and the more regular and reasonable people exercise, the better the condition of their joints. I hope everyone can find a sport that suits them, participate in it, and stick to it, so that our joints can live longer!

Planning and production

Author: Huang Tao, Head of the Sports Medicine Rehabilitation Department at the Chongli Branch of Peking University Third Hospital

Reviewer: Ji Gang, deputy chief physician of orthopedics, the First Hospital of Hebei Medical University