My 23 month old grandson broke his upper femur and was in a double leg cast (bellybutton to ankles) for 6 weeks. The cast is off, but he is unable to stand yet--only does what we call the army crawl. The doctor said to let him do what he wants in the activity area. He will try to stand on his own, etc. What physical therapy exercises can we do to assist his "getting back to normal"? I know we don't want him running right away but we do want to help him as much as possible.