It could be a lot of things. I agree with the above posters who say your child should be evaluated. My son has motor skills issues which are a problem with his tendons. He needs to type instead of write because he cannot control a pen or pencil. His legs needed to be in casts for months to stretch his tendons. He's 17 and still walks on his tippy toes from the tendon issues and also it's an aspergers thing from what I've been told. He had very delayed speech and liked to play on his own. He couldn't read or even talk but would sit with books for hours flipping the pages and staring intently at words he didn't understand. He enjoyed it. My son has aspergers and physical issues.