Many of us cross our legs unconsciously during the day. One research reported that 45% of women and 21% of men cross their legs nearly all the time. There are also many ways to cross legs. We can cross our legs at the knees or cross at our ankles. But is crossing our legs really bad for us? Let’s explore some of the thoughts behind the theories proposed for not crossing your legs.
1. Increases Blood Pressure: There have been at least seven studies performed that show that blood pressure does increase when people crossed their legs. However, and more importantly, the blood pressure went back down to previous levels after the subjects uncrossed their legs and blood pressure was re-measured a mere 3 minutes later. Crossing your legs thus may lead to brief temporary increases in blood pressures. Those with a history of high blood pressure demonstrated the greatest increases in blood pressure when their legs were crossed.
2. Varicose Veins: There is no scientific proof that crossing your legs increases the pressure enough in your legs to cause varicose veins. Varicose veins are due to weakened valves within the veins such that there is insufficiency of blood being pumped upwards from your legs into the main part of the body. The blood becomes more engorged in the veins pushing the walls outwards like a balloon giving the appearance of the varicosities.
3. Causes nerve damage: Placing steady pressure on the outer part of your leg below your knee can lead to irritation of the peroneal nerve causing your lower leg and foot to go numb. Sensation however will return within a few minutes of relieving direct pressure over the area. What about in yoga and sitting cross-legged for hours? Prolonged greater than 3 hours of pressure could contribute to peroneal nerve palsy causing foot drop. However staying in exactly one position is rare, as most people will frequently shift body positions to stay comfortable.
4. Leads to bad posture: There is some merit to this. When one crosses their leg especially for accumulatively more than 3 hours a day, they will likely at some point, assume other poor postures such as rounding their back. When you round your back, your shoulders also roll forward, your chin juts forward and the natural small of your back i.e. lumbar lordosis is reduced. This posture adds more stress on the spine, its discs and nerves traveling out from our spinal cord.
5. Causes muscle imbalance and pain: An interesting study performed at the University Medical Centre in Rotterdam embalmed pelvises replicating different sitting positions. They found that the piriformis muscle in our buttock was tighter by 11% in the group that crossed their legs at the knee compared to the group that kept their legs straight. The authors of the study proposed that the piriformis tightness contributed to pelvic stability similar to contracting the abdominal muscles. As a physical therapist, I would advocate for strengthening your abdominal muscles. Piriformis syndrome is when the piriformis is tight and spasming causing low back pain and possibly sciatica. If you have a history of low back pain and are experiencing a flare up, consider not crossing your legs as doing so may contribute to further irritation to inflamed muscles.
6. Causes blood clots: Those who are at risk for deep vein thrombosis, DVT should heed the warnings to not cross their legs especially for long periods. This is due to the fact that people at risk for DVTs have in essence a higher chance of developing blood clots in their calves. With the increased pressure placed by crossing your legs, blood circulation is impeded and there is then a higher chance for the blood to in essence “stick” to one another and form a clot. That clot can then travel other parts of your body causing worst problems such as a pulmonary embolism.
In summary, periodic crossing of your legs will unlikely cause long-lasting harmful effects. If you are experiencing pain especially in the low back or hip pain, consider how crossing your legs can contribute to bad posture habits and irritate existing muscles. The best solution is actually to minimize your sitting and get up and move!