Spend time on any crowded sidewalk and you’ll see heads bent over and eyes cast downward. One recent study of college students found that a quarter of people crossing intersections were glued to a device.

“I don’t think people are aware of how much they’re distracted and how much their situational awareness changes when they’re walking and using a phone,” said Wayne Giang, an assistant professor of engineering at the University of Florida who has examined the link between phone use and walking injuries.

Indeed, our devices can cause what some experts call “inattentional blindness.” One study found that participants were half as likely to notice a clown on a unicycle — a cheeky touch — while walking and talking on a phone.

But that screen in your hand isn’t just diverting your attention. It also changes your mood, your gait and your posture — and hinders your ability to get from point A to point B without running into trouble.