My nephew will be 7 years old and has started running with a slight limp. He seems weaker and slower than he used to be. He was checked by his family doctor and even saw an orthopedic doctor. Is there anything that could be causing his weakness besides muscular dystrophy? What about hyper mobility? Years ago he was diagnosed with sensory perceptive disorder and teachers believe he has ADD, but is currently not on medication. I'm just trying to educate myself so I can help my sister. I believe they are scheduled to see a neurologist in November to hopefully find out more.