If you're one of the millions of people who spend two to four hours each day hunched over their smartphones, you're at risk for what researchers call "text neck"—poor posture that puts intense weight on your cervical spine. According to a recent study, inclining your head at a 15-degree angle adds 15 pounds to your spine; a 60-degree angle ups that number to 48. That's the equivalent, one physical therapist says, of bending a finger all the way back and holding it there for an hour.
Whether you're answering studio emails, texting to find a last-minute sub or posting to social media, make sure you're only looking down at your device with your eyes—not by craning your neck. And warn your students, too: High schoolers spend even more time on their phones, research shows, which means they're at greater risk.