You may really dislike this advice if you’re an avid leg-crosser. It can be a tough one to accept, but ultimately, crossing your legs really isn’t very good for you.
Part of the reason why is simply the act of sitting for hours at a time during the day (which is an entirely separate discussion that I’ll save for another time). But even more so, when we try to isolate the action of sitting with legs crossed, we see that it can create some significant imbalances in the pelvis, which then gets distributed throughout the body.
Where the Problems Start
When the vast majority of us cross our legs, whether it’s left over right or vice versa, we usually stick to the one habitual crossing arrangement. If you change it up regularly, then kudos to you, but it’s still not ideal.
The leg that we take over the top undergoes some slight external rotation, adduction, and some extra flexion at the hip. Here’s a fun fact about flexion: when the hip is in flexion deeper than 90 degrees, the piriformis muscle (the primary external rotator when we’re standing) actually switches to become an internal rotator. Yep — take it from me, it’s as bad as it sounds.
To understand the anatomy and physiology of this phenomenon, please watch this video, but it basically means that the piriformis of the leg on top gets lengthened when you’re crossing your legs. The leg on the bottom, on the other hand, doesn’t get that much movement at all.
How it Gets Worse
Over time, we repeat this action the same way every day, year after year. We create slightly more habitual length in one side compared to the other. This means, relative to the top leg, the other piriformis can be, as they say, “tighter.” This imbalance of muscle mobility ends up creating an imbalanced system of pull on the sacrum, causing the pelvis to be pulled slightly off-centre as a result.
Because our bodies are specifically designed for compensation, the imbalance doesn’t just stay in the hips — it spreads over time. It’s particularly common for your shoulders to attempt to rectify the situation by shifting themselves to account for the imbalance in your pelvis. Essentially, this means that sitting with your legs crossed can even contribute to that shoulder and neck pain you’ve been feeling for years.
Not only that, but crossing your legs has been shown to slightly increase the level of vascular pressure in the lower limbs. While the effect is relatively small compared to some other influences of local and systemic blood pressure, over time, this can contribute to a greater prevalence of spider vein formation and visibility.
How to Break the Habit
Something as basic as sitting habits can be pretty tough to retrain, but it all starts with awareness! Now that you know that crossing your legs is really not that great for you, you’ll gradually begin to notice the pains and tensions as you automatically do it throughout the day. That’s a start!
One of the best ways to eliminate the chance of crossing your legs is to switch out your chair for an exercise ball. Ever tried to sit on one of those with your legs crossed? You’ll either develop an incredibly strong core (yay!) or you’ll fall off and never do it again (also yay! Except for the falling part). Oh, and by the way — getting those balls with a chair back and rolling feet defeats the entire purpose.
Another little trick is to have your colleagues read this, too, so you can begin to hold each other accountable! Teamwork promises make it much easier to change up any pesky habit. Remember to be nice about it, of course, and that new habits take time to form, so don’t get too upset when you catch yourself with folded legs.
Okay, now you’re ready to straighten everything out. Good luck!