◎Hardy
"Men shake their heads when they are poor, women shake their base", this popular saying associates the body movement of "shaking their legs" with social status. It is often used by elders to admonish children and persuade them to change their "love" Shaking your legs is an uncivilized habit. Why do people cannot help but step on the "void pedal" at certain moments?
Can't help but shake the legs, maybe emotions are causing trouble.
In fact, leg shaking is a typical body language. When it appears, it often means that the person shaking the legs is in a state of nervousness, boredom or high excitement. For example, some studies have shown that during exams, low-scoring candidates who feel anxious can't help but shake their legs, while confident high-scoring candidates do not move their legs too frequently.
To explain why people like to shake their legs when faced with stress, we need to start with a concept proposed by physiologist White Cannon in 1929: When animals perceive stress or survival threats, they will release under the action of sympathetic nerves Adrenaline produces physiological reactions such as accelerated heartbeat, elevated pulse, and more blood flowing to the limbs. This physiological reaction helps animals respond quickly when danger comes and helps them survive better. Cannon named this concept the "fight-flight" response, or the "fight-or-flight" response. Because this is a "life-saving" mechanism in which the body responds to survival before the brain does. It once helped human ancestors in ancient times escape natural enemies or compete for survival resources. Therefore, it has been preserved during the long evolution and is secretly used as "when quarreling." "Rapid heartbeat", "blushing when expressing love", "wanting to have diarrhea when nervous" and many other forms continue to accompany us.
What is the connection between the "fight or flight" response and leg shaking? In a health advisory for the British Metro newspaper, counselor Dawn Templeton and clinical psychologist Catherine Hackel expressed their views: In states of stress and anxiety, adrenaline and cortisol accumulate, The body accumulates energy under the action of the "fight or flight" response and prepares itself to fight stress. But when we don't use up this energy through self-defense or escape, excess energy remains in our bodies, and leg shaking is one way to release that energy. In other words, shaking your legs is like a fake action used by your brain to deceive yourself. Since your butt still needs to sit on the chair, you can reluctantly vent your excess energy by shaking your legs.
also shakes his legs when he is bored. Some studies have shown that when the mind starts to wander, the body will also "dissipate" and make small movements. This may be because boredom can bring anxiety and frustration to people, causing stress hormones to accumulate, and body movements such as shaking legs, playing with hair, and turning pens can help release stress. However, it should be noted that repeating these behaviors for a long time will form a fixed habit. If you forcefully correct it at this time, it will increase the irritability. For example, if a person has the habit of shaking his legs, if he deliberately reminds himself not to shake his legs during an important interview, he may become restless or even ruin the entire interview.
In addition to shaking their legs when they are anxious, when listening to their favorite music, people will also shake their legs unconsciously to the rhythm of the melody. This is because music is a special sensory stimulation that activates body movements in people's unconscious state. In addition, researchers from the University of Oslo in Norway found that shaking legs regularly to the rhythm of music can help the brain better understand music.
Leg shaking is very comfortable, and may improve the harm caused by sitting for a long time.
Leg shaking is not only a very natural behavior, but also by shaking the legs, the brain will secrete dopamine and other hormones related to pleasant emotions, creating a "good" feeling.
But some people may worry about whether shaking legs will cause health hazards? In fact, proper exercise of the muscles through movements similar to leg shaking may alleviate the damage caused by sitting for a long time.
Researchers at the University of Missouri recruited 11 volunteers and used ultrasound and blood pressure cuffs to measure blood flow in the main arteries of each person's legs under normal circumstances. The volunteers were then asked to sit quietly in front of the table for three hours. During this period, one leg was kept absolutely still, while the other leg was shaken from time to time (shake for 1 minute and stay still for 4 minutes).The results showed that compared with the initial value, the blood flow of the stationary legs was significantly reduced; while the blood flow of the legs that shook from time to time increased.
Another study from the University of Houston found that if sedentary people effectively exercise the soleus muscle on the calf, it can also improve muscle metabolism and even improve blood sugar and blood lipids. This method of training the soleus muscle is very similar to leg shaking, that is: maintain a sitting position, relax your feet first, then lift the back heel and keep the toes on the ground. When the back heel reaches the limit and the soleus muscle has an obvious stretch, , then the heel falls back to the ground.
However, it should be noted that the sample sizes of these two sets of studies are small and can only provide limited reference value. And if you want to completely avoid the health damage caused by sitting for a long time, the best way is to stand up and move around.
Generally speaking, although the small action of shaking the legs can be beneficial to the body and mind in some specific situations, you need to pay attention to the posture and the occasion. After all, frequent leg shaking expresses irritability with body language, which is an impolite behavior. Therefore, instead of developing the habit of shaking your legs, it is better to learn scientific relaxation methods.
Pathological leg shaking needs to be treated with caution
Although physiological leg shaking is basically harmless except for cultural impoliteness, pathological leg shaking is related to certain diseases and needs to be carefully identified for early treatment.
The most typical clinical disease of leg shaking is restless legs syndrome, which is a sensorimotor disorder. Simply put, the patient will feel indescribable abnormal sensation and discomfort in both lower limbs in a quiet state. Shaking it constantly or tapping it a few times can relieve the pain. The biggest characteristic of this disease is that it worsens at night.
Leg shaking is also a common self-stimulation behavior among patients with autism. Autistic patients often feel anxious and overwhelmed by external noises or lights. Self-stimulation behaviors including shaking legs, rubbing hands, biting fingers, etc. can help them distract their attention, calm their emotions, and regain a sense of control over their bodies. . Similarly, people with ADHD and anxiety disorders often shake their legs to cope with anxiety and focus.
(The article comes from the WeChat public account Popular Science China)
