Boy! I never saw this one coming.

In just the latest reason why you should probably cut down your kid's screen time, experts are saying that all that swiping has rendered a generation of screen-savvy toddlers so weak that they can't hold a pencil.

Pediatricians, orthopedic specialists, and handwriting experts have joined forces to warn parents of the dangers of touch screens, and to recommend that kids also get experience with traditional writing implements and motor skill-enhancing toys like blocks and modeling clay.

"It's easier to give a child an iPad than encouraging them to do muscle-building play such as building blocks," said Sally Payne, of the Heart of England National Handwriting Association (NHA).

She warned that too much tapping and swiping atrophies the muscles in the wrist, elbow, and shoulder, leaving many preschoolers too weak to properly grasp pencils and crayons when they reach preschool.