Posted on 17th Nov 2011 @ 6:08 AM

We all know how we're supposed to sit at our desks: Feet flat on the floor, thighs parallel to the floor, elbows bent at a 90-degree angle. But even with ergonomic chairs, keyboard trays, and all the other gadgets we have to help us sit correctly, how many of us actually sit the way we're supposed to? Here are five of the worst desk posture habits.

1. Slouching.

The bane of your Mom's existence -- slouching -- does more than put stress on your joints. Researchers at the University of Leeds have found a connection between the muscles in your neck and your nucleus tractus solitarius (NTS) -- the part of the brainstem that helps regulates blood pressure.

2. Crossing your legs.

It's a myth that crossing your legs causes varicose veins, but this comfortable position can have negative consequences. Spider veins -- those tiny red squiggly lines that probably inspired the invention of pantyhose -- are more common in women than in men, in part because of the leg crossing habit. And crossing your legs definitely contributes to lower back pain.

3. Making like a turtle.

Forward head posture is common among people who sit at desks all day. In addition to making us look like Yertle the Turtle, it's pretty bad for just about every part of your back. Forward head posture causes headaches, neck and shoulder pain, upper back pain, and permanent curvature of the upper back. And don’t forget that it makes us look like Yertle. Pain is one thing, but vanity is eternal.

4. Sitting cross-legged.

This one makes us sad. Sitting cross-legged seems like it should be healthy -- it's practically yoga! It should probably make you thinner, too. Unfortunately, what it does is wreak havoc on your knees. Darn, knowing things. 

5. Not taking a break.

Maybe the worst habit of all: Sitting all day long without taking a break. Experts say that you should take a break every 20 minutes at most, stand up, stretch and walk around.