Why Can’t I Stop Bouncing My Leg? A Neuroscience Expert and Psychoanalyst Explain the Common Habit
Many habits come and go. Bitter polish rid me of nail biting; a teasing grandmother freed me from nervous knuckle cracking. But there is one that has stuck around for as long as I can remember—I am *always* shaking my leg whenever I’m sitting down. Sometimes it’s a loose bounce from the knee; other times it’s more my foot and ankle that are rapidly tapping.
In coffee shops, on dates, while riding the subway, and throughout work calls, this fidgeting is so omnipresent that I rarely notice it until a friend places a steadying hand on my leg to quiet the tapping. This habit isn’t unique; my dad, brother, and several friends do it, too. Why do we subconsciously shake our legs? And is there anything that can be done to tame the habit? I spoke to a psychiatrist and a neuroscience expert to hear what they have to say about this common tic.
As I started working on this story, I spent two weeks tracking the when, where, and why of the habit. I’d be waiting for a friend at a cafe and left alone with my mental to-dos for a moment too long… and my boot would start clicking against the table. Or I’d be on a Zoom call listening to person after person present, knowing that my turn is approaching; with a mix of nerves and anticipation… tap, tap tap.
I first wondered if there were any external factors that impacted my bouncing leg. But I found that the habit doesn’t discriminate based on location, time of day, whether or not I have company, or what shoes I’m wearing. (I send my condolences to anyone that’s been around me during my vintage tap shoe loafer phase.)
However, I did find a trend in how I was feeling. I was typically bored; tired; feeling anxious, stressed, insecure; in physical pain; or excited.
What causes leg bouncing, according to science?
There can be a number of reasons why we end up bouncing our legs without thinking about it. Getting to the source can be the key to calming the shake.
Stress and anxiety
Anxiety disorders affect more than 31 per cent of the U.S. population, according to the National Institutes of Health. The increased cortisol levels mean a higher heart rate and a compensatory need to move or “let it out.” That’s because movement increases blood flow and can release tension that is being stored in muscles, making tapping a good coping mechanism.
“In fact, doctors encourage exercise, because it regulates anxiety and mood [and] leg shaking is, in a certain sense, a form of exercise,” explains Cheryl Collins, MD, a top psychiatrist and psychoanalyst. “One way of thinking about it is as a mini HIIT.”
As psychologist Serenity Serseción, PhD, previously told Well+Good, fidgeting “has a similar but smaller effect to exercise when it is not possible, such as in a work situation.”
An attempt to concentrate
According to a 2015 study, “research in children with attention deficit hyperactivity disorder (ADHD) suggests that repetitive movements improve concentration and attention.” This same effect could account for the increased incidents of leg shaking while working from home. Dr. Collins explains that the stimulus can help quiet restless or hyperactive parts of the brain and even help with focus, especially when dealing with a “negative stimulus” such as boredom or distraction.
Too much caffeine
Another contributing factor could be your soda or coffee intake. “The consumption of stimulants, such as caffeine, has the potential to intensify the rate and occurrence of leg shaking,” both because it is a neurological stimulant and because increased caffeine intake is often linked to fatigue or exhaustion—factors that exacerbate restlessness, brain fog, trouble focusing, and anxiety, notes Better Help.
A need for physical release
Recently, I’ve been nursing a hip and spine injury that has forced me to take a step back from running—formerly, an integral part of my morning routine that rid me of a lot of pent-up energy. Without it, that energy has had nowhere to go and neuroscience expert and founder of BrainTap, Patrick Porter, PhD, explains that I’ve likely been using my leg bouncing as “a subconscious means of physical release.”
