I have been working in the Human Services field since 1996, primarily working with people with developmental disabilities.
You have probably noticed, especially if you've found your way to this article, that some people shake their legs a lot. You might be sitting in the waiting room at the doctor's office, in the lobby waiting to be seated at the restaurant, in class; the guy or gal next to you is bouncing his or her knee or shaking their legs back and forth, appearing agitated or, maybe bored. Depending on your temperament or own idiosyncrasies, you might find it annoying or curious. Either way, you have probably asked why do people shake their legs.
There are several possibilities which we will now explore.
Many people find it easier to concentrate if they are doing something physical. You might go for a walk to think about a heavy issue that you're dealing with. If you are stuck at a desk in class, presented with a difficult task, you might shake your legs. Maybe even wring your hands.
Research has shown that there are overlaps in the areas of the brain that deal with motor functions and cognitive functions, so it's reasonable to assume that doing something physical might actually help you think.
It seems that if something is hard to do, there is a tendency to want to release nervous energy or even to run. Shaking your legs gives you a physical activity you can control without just running away.
Some people get bored easy and have a lot of energy and are physical. If the situation is under-stimulating to them, they might, essentially, compensate by shaking their legs.
Considering our current environment of heavy-duty stimulation, constantly, from various devices, the Internet, phones, etc. it is likely most people are accustomed to a quick and heavy dose of stimuli on a regular basis. If it all slows down and is less dramatic, one might engage body parts to make up the difference.
Of course, this can also happen if someone is overstimulated. Many of us have had the urge to move when there's too much going on.
Someone using some kind of stimulant, such as coffee or nicotine, can get a bit agitated and shake their legs when sitting. Of course, the stronger the stimulant, the worse the agitation.
Disorders and Disabilities
There is a host of conditions and disorders that might cause someone to shake their legs a lot.
Restless Leg Syndrome might be the most obvious one. With this disorder, the person gets an uncomfortable feeling in the legs and will often deal with it by shaking their legs. It modulates the "creepy" feeling in the legs and offers relief. In fact, the more still and at rest they are, the creepier the feeling gets; this is why they will often have the antsy feeling in their legs when they've gone to bed for the night.
People who have Attention Deficit Hyperactivity Disorder or Attention Deficit Disorder will often shake their legs too. They feel like they have to move and one way they alleviate this urge is to shake their legs.
People with Autism often display repetitive movement and behavior, called stereotyped movements, often for the purpose of self-stimulation, in the field often referred to as "stimming". People with Autism are very sensitive to stimuli but also like to have control of it; they will repeat a movement over and over again as a way to self-soothe themselves.
Of course, someone dealing with anxiety will also shake and fidget to deal with their stress.
Generally you will see that this behavior tends to be a coping mechanism. Probably this is true no matter what the source of the behavior is.
Great Explanation of Stimming
So, there it is. People who shake their legs a lot could be stressed, they might be trying to focus on something, could be using stimulants or might have a condition like Restless Leg Syndrome, Anxiety or perhaps they are engaging in "stimming" because they have Autism.
Understandably, I suppose if you're observant, it does make you wonder why someone might shake their legs for no apparent reason; however, it appears there are various possible reasons for it.
Ronald Hart on April 11, 2019:
An informative piece of content.
pen promulgates on June 16, 2017:
I shake my legs too.
I guess I can relate to: very active physically, attention deficit. (not that I am physco, just too distracted) he he
My nephew is autistic though..
Nathan Bernardo (author) from California, United States of America on December 06, 2016:
Thanks, Roberta, much appreciated, I'm glad you had insight into this Hub and glad you liked it.
RTalloni on December 06, 2016:
The way you've covered this topic reminds me that we need to be careful not to make assumptions about people's behaviors. Thanks!
Nancy Yager from Hamburg, New York on November 14, 2015:
People with hyperthyroidism (Overactive thyroid) will often shake their legs.
Nathan Bernardo (author) from California, United States of America on August 09, 2015:
You're right, we've all seen people shake their legs, and I too have shaken my foot in bed. Glad you stopped by and glad you liked the article.
Missy Smith from Florida on August 09, 2015:
This was interesting. I think we have all been around someone at sometime that shakes their leg manically. I, actually, don't do this often during the day, but at night in bed, I shake my foot, not my leg, but I will move my foot back and forth. It helps me relax myself to sleep.
Interesting article. :)
peachy from Home Sweet Home on April 16, 2015:
it is a bad habit hard to break. Once, I kept swinging my legs thru and fro when eating dinner. My mom had to shout at me and smack my legs till they hurt. I had stopped swinging or shaking
Ensorcelie from Albania on April 15, 2015:
I shake them when:
I am bored.
I am cold.
I have been sitting for a long time in a classroom.
I can't wait for something to happen.
I have anxiety.
and lastly: when I get bored again.
Nathan Bernardo (author) from California, United States of America on March 03, 2015:
No problem, Rodric. Thanks for stopping by.
Rodric Anthony from Surprise, Arizona on March 03, 2015:
I shake my legs due to pain from Neuropathy. It is mostly at night. Thanks for posting this article. It is informative.