My knee suddenly 'soft' when walking, what's the matter? Two signals or the knee is calling for help

Uncle Chen has not done any exercise since he retired at the age of 60. He believes that the old man's rest is the only way to maintain health. Exercise can easily hurt the knees. People who exercise regularly must have bad knees, especially if they fall down one day, they will be troublesome. .

But recently, Uncle Chen always feels numb in his knees, like a lot of ants crawling around. One day, when Uncle Chen was going down the stairs, his knees suddenly became "soft" and he almost fell to the ground. Fortunately, Uncle Chen grabbed the handrail in time.

My knee suddenly "soft" when walking, what's the matter? Who has worse knees, a regular runner or a sedentary person?

1. The best condition of the knee joint is only 15 years

The knee joint is the largest and most complex joint in the human body. It consists of the medial and lateral malleolus of the femur, the medial and lateral malleolus of the tibia, and the patella. Its main function is to bear weight and coordinate the activities of the lower limbs.

Our daily activities add to the burden on the knee joint, causing wear and tear on the knee, and this damage is irreversible.

For example, the pressure value of lying position is 0, standing and walking are about 3-4 times body weight, running is about 4 times body weight, playing ball is about 6 times body weight, and squatting and kneeling are about 8 times body weight.

According to data from Life Times, before the age of 15, the knee joint is in the developmental stage. By the age of 15-30, the knee joint is at its best. At the age of 30-40 years, the knee joint begins to show early mild wear and softening of the patella, and vigorous exercise needs to be reduced at this time.

When I am 40-50 years old, the knee joint is worn out, and it may be manifested as low back pain after walking a long distance, but the pain can be relieved after rest. After the age of 50, there may be significant pain in the knee joint. At this time, the "service life" of the patellar cartilage has almost reached its limit.

Under normal circumstances, the best state of the knee joint is only 15 years. After the age of 30-40, the knee joint can no longer be used arbitrarily.

2. A person who runs regularly and a person who does not exercise for a long time, whose knee is worse?

Some people say that running hurts the knees, but according to research in the United States, sitting for a long time can hurt the knees more than running.

The study was published in May 2017 in the authoritative medical journal "Journal of Orthopedics and Sports Physiotherapy" by researchers from the United States, Canada, Spain and Switzerland. The researchers reviewed 25 studies including 125,810 people, and selected 17 studies with a total of 114,829 people for meta-analysis.

The study found that only 3.5 percent of recreational runners had hip or knee arthritis, compared with 10.2 percent of sedentary people who didn't run, and 10.2 percent of professional runners who ran more than 92 kilometers per week. The rate is as high as 13.3%.

The reason why sitting for a long time can hurt the knee is that the normal nutrition metabolism of cartilage depends on proper exercise. When we exercise, the body will repeatedly squeeze the cartilage, prompting the cartilage to repeatedly squeeze and absorb the synovial fluid, thereby expelling the cartilage metabolic waste and absorbing the nutrients and oxygen in the synovial fluid.

Therefore, moderate exercise is more protective of the knees than sitting still. The early degeneration of the knee joint is generally asymptomatic, but there are two signals that may be the distress signal of the knee joint.

· Unexplained pain upstairs or downstairs

·It doesn't hurt when you press it, it hurts when you press it

3. The knee suddenly softens when walking, and there are several reasons why the knee can't run away

Some friends often suddenly feel weak in one leg, unable to exert force on the knee joint, and feel like they are about to kneel. The main reasons for a weak knee are as follows:

· Bone hyperplasia

Bone hyperplasia is one of the normal degeneration phenomena of human aging. When the knee joint develops bone hyperplasia (commonly known as "bone spur"), sudden leg weakness may occur, and this kind of bone spur occurs in middle-aged and elderly women. This is because the aging and degenerated cartilage will produce loose bodies. When these free substances stimulate some tissues around the knee joint, it may cause the surrounding muscles to spasm and cause leg weakness.

· Knee osteoarthritis

People who often walk, climb or climb stairs may use the knee joint frequently for a long time, which may lead to congestion of the tissues around the knee joint and then inflammation.

Knee pain and leg weakness can occur if knee osteoarthritis is left untreated. Although this will not affect the movement of the knee joint, it will cause great inconvenience to life. Once the leg is straightened, the knee joint will be painful.

· Meniscus damage

Meniscus injuries are very common. When the lower extremity is loaded, the foot is fixed and the knee is slightly bent, if there is a sudden excessive internal rotation or external rotation and extension of the knee (common in badminton and basketball), it may cause a meniscus tear. crack.

When a meniscus injury occurs, there is obvious leg weakness when walking on a flat road, sometimes accompanied by symptoms such as joint pain, limited movement, and snapping during movement.

· Knee ligament injury

When the knee joint is slightly flexed, its stability will be relatively poor. If a sudden external force causes varus or valgus, it may cause damage to the medial and lateral collateral ligaments and cruciate ligaments, making the knee joint unstable and damaged. The legs will feel that they are afraid to exert force, and at the same time, they will obviously feel that the injured legs are weak. When walking, they will be soft, and the knee joints will feel wrong, and some of them may swell.

· Cerebral infarction

In addition to the reasons for the knee joint, when a cerebral infarction occurs, because the brain cannot control the movements of the limbs, the balance of the body may not be well controlled when walking. At this time, the limbs will appear hemiplegia or the strength between the muscles will decrease, and the legs may also be weak. Case.

4. Walking posture can suggest health status

Sometimes, a person's walking posture can also tell their physical health. If you experience the following abnormal symptoms while walking, it may be a sign of disease.

1. Walking with a limp and swaying from side to side

If one arm swings normally while walking and the other arm barely moves, this asymmetrical movement may also be a common symptom of Parkinson's.

2. Walking on flat ground always stumbles

Walking on a flat bottom always stumbles, which may be due to motor nerve damage, such as cerebellar atrophy caused by aging, nerve damage caused by long-term alcoholism, and cerebellar dysfunction caused by cerebral infarction and cerebral hemorrhage.

3. Walking is always sore and sore in the legs

When walking, if you walk for a long time, you will feel leg pain and leg pain, which may be caused by flat feet. Because the arches of people with flat feet are very low, and some people even have no arches at all, there is no cushioning when walking, and every step hits the ground firmly, so when standing or walking for a little longer, The legs will feel very tired and easily feel sore.

4. The soles of the feet will twitch when walking

If you feel the soles of your feet twitch when you walk or stand up, as if a needle pierced the soles of your feet and feel numb, this is probably caused by "plantar fasciitis" (also known as "heel pain") of.

The plantar fascia is a layer of elastic membrane located under the arch of the foot, which plays a role in maintaining the height of the arch of the foot. When we walk or run, the arch of the foot will change its height repeatedly, for example, the arch of the foot will recover when the foot is lifted, and the arch of the foot will become flat when the foot is on the ground. Once the fascia is stretched repeatedly with excessive exercise, strain or chronic inflammation can occur.

The knee joint has a complex structure and is prone to injury. When any part of it is degenerated or injured, it is likely to cause instability or pain in the knee joint, and sudden knee weakness when walking.

References:

[1] From the way you walk, you can see that the knee joint is severely "worn". Life Times, 2022-01-17

[2]Running and Osteoarthritis： Does Recreational or Competitive Running Increase the Risk？. J Orthop Sports Phys Ther. 2017;47(6)：391. doi：10.2519/jospt.2017.0505

[3] Take a step and kneel, your legs are weak, or your knees are crying for help! .Family Doctor Online, 2021-03-06

[4] Health status can be seen from the walking posture! Pay attention to these 10 situations! .Health Times, 2022-03-28

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