Toe walking is one of the signs of muscular dystrophy. As the muscle weakens the child will come up on his toes to compensate. There are of course other signs such as enlarged calf muscles, a sway in the lower back making the belly seem to protrude, difficulty getting up from the floor, tiring easily, and trouble keeping up with others while walking or running. I blood test can be done to check the ck level, if muscles are being damaged this level will be elevated. The test is relatively inexpensive. If your child is toe walking I would look for these other symptoms.