Your head weighs about 10 pounds, and experts say every inch you tilt it forward doubles the pressure on your spine. So, if you're hunched over while texting on your smartphone or playing games on your tablet computer, your neck is supporting the equivalent of 20-30 pounds.
That strain can cause neck pain or even pull your spine out of alignment. Slouching also reduces your lung capacity by 30 percent. So straighten up. Sit with your feet ﬂat on the ﬂoor and roll your shoulders back. Instead of looking down at your mobile device or tablet, hold it at eye level. And don't sit too long: take breaks every 20-30 minutes to stand, stretch and walk around.