When walking, the knee suddenly 'soft', what's the matter? Two signals or the knee is calling for help
Uncle Chen has stopped doing any exercise since he retired at the age of 60. He believes that resting for the elderly is the best way to keep in good health. Exercise can easily hurt your knees. People who exercise regularly will definitely have bad knees, especially if they fall down one day. .
But recently, Uncle Chen always feels numb in his knees, as if there are many ants crawling around. One day, when Uncle Chen was going down the stairs, his knee suddenly "softened" and he almost fell to the ground. Fortunately, Uncle Chen grabbed the handrail of the stairs in time.
When walking, the knee suddenly "soft", what's the matter? People who run regularly or those who sit for a long time, whose knees are worse?
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 is composed 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 will increase the burden on the knee joint and cause wear and tear on the knee, and this damage is irreversible.
For example, the pressure value of lying position is 0, standing and walking is about 3-4 times of body weight, running is about 4 times of body weight, playing ball is about 6 times of body weight, and squatting and kneeling is about 8 times of 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, the knee joint begins to show early mild wear and tear, and the patella softens. At this time, strenuous exercise needs to be reduced.
When you are 40-50 years old, the knee joints are worn out, and you may experience low back pain after walking a long distance, but the pain can be relieved after rest. After the age of 50, there may be obvious pain in the knee joint. At this time, the "service life" of the patella cartilage has almost reached the 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 as one likes.
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 can hurt your knees, but according to the results of a US study, sitting for a long time hurts your knees more than running.
The study, by researchers from the United States, Canada, Spain and Switzerland, was published in the prestigious medical journal Journal of Orthopedics and Sports Physiotherapy in May 2017. The researchers reviewed 25 studies involving 125,810 people, and finally selected 17 studies with a total of 114,829 people for meta-analysis.
The study found that the incidence rate of hip or knee arthritis in recreational runners was only 3.5%, while the incidence rate in sedentary and non-running groups was 10.2%, and the incidence rate in professional runners (running more than 92 kilometers per week) The rate is as high as 13.3%.
The reason why sitting for a long time will hurt the knees is that the normal nutrient 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, so as to discharge the cartilage metabolic waste and absorb the nutrients and oxygen in the synovial fluid.
Therefore, moderate exercise protects the knees better 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 going up or down stairs
· No pain if you don't press it, it hurts when you press it
3. When walking, the knee suddenly becomes soft, and there are several reasons why you can’t run away
Some friends often experience sudden weakness in one leg, unable to exert force on the knee joint, and feel as if they are about to kneel down. Some people also feel severe pain when their legs are weak, and even actually fall down. The main causes of soft knees are as follows:
·Bone hyperplasia
Bone hyperplasia is one of the normal degenerative phenomena of human aging. When bone hyperplasia (commonly known as "bone spur") occurs in the knee joint, sudden leg weakness may occur, and this kind of bone spur is more likely to occur 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.
· Osteoarthritis of the knee
People who often walk, climb mountains or climb stairs at ordinary times may cause tissue congestion around the knee joint due to long-term high-frequency use of the knee joint, which may lead to inflammation.
If knee osteoarthritis develops and goes untreated, knee pain and leg weakness may occur. 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.
· Meniscal injury
Meniscus injury is very common. When the lower limb is loaded, the foot is fixed and the knee joint is slightly bent, if the knee is suddenly excessively internally rotated or externally rotated to extend the knee (common in badminton and basketball for offense and defense), it may cause a meniscus tear. crack.
When a meniscus injury occurs, there will be obvious leg weakness when walking on flat roads, sometimes accompanied by symptoms such as joint pain, limited motion, and snapping when moving.
· Knee ligament injury
When the knee joint is slightly bent, its stability will be relatively poor. If a sudden external force causes varus or valgus at this time, it may cause damage to the medial and lateral collateral ligaments and cruciate ligaments, making the knee joint unstable and damaged The leg will feel afraid to use force, and at the same time, it will obviously feel that the injured leg is weak, and it will be soft when walking, and the knee joint will feel wrong, and some parts may even swell.
· Cerebral infarction
In addition to the cause of the knee joint, when a cerebral infarction occurs, the brain may not be able to control the movement of the limbs, and may not be able to control the balance of the body when walking. At this time, the limbs may experience hemiplegia or the strength between the muscles will decrease, which may also cause the legs to become weak Case.
4. Walking posture can imply health status
Sometimes, a person's walking posture can also reveal their physical health. If the following abnormal symptoms appear when walking, it may be a signal of disease.
- Walking with a limp and shaking from side to side
Asymmetrical movements of one arm while walking can also be a common symptom of Parkinson's if one arm swings normally and the other barely moves.
- Walking on flat ground always stumbles
I always stumble when walking on a flat bottom, 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.
- My legs always hurt when I walk
When walking, if you walk too much, you will feel pain in your legs and sore legs, which may be caused by flat feet. Because the arch of the foot of patients with flat feet is very low, some people even have no arch at all, which leads to no cushioning when walking, and every step is firmly hit on the ground, so when standing or walking for a long time You will feel that your legs are particularly tired and prone to soreness.
- The soles of the feet will twitch when walking
If you feel numbness in the soles of your feet when walking or standing up, as if a needle has been pricked in the soles of your feet, it is likely to be 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 are walking or running, the arch of the foot will change height repeatedly. For example, the arch of the foot recovers when the foot is lifted, and the arch of the foot flattens when the foot is stepped on the ground. Once the fascia is repeatedly stretched by excessive exercise, strain or chronic inflammation may develop.
The knee joint has a complex structure and is also prone to injury. When any part of it degenerates or is 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 joints are "weary". 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 asking for help! .Family Doctor Online, 2021-03-06
[4] You can see your health status from your walking posture! Pay attention to these 10 situations! .Health Times, 2022-03-28
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