Get checked out by an orthopedist, if he says that there is some damage/injury, then you need to call an attorney that you know, not one of those ambulance chasers who advertise on t.v. Ask your friends or a lawyer you have used in another field to recommend an attorney. I'm sure there is a rating site somewhere if you don't know of anyone who has used a personal injury lawyer in the past. You don't want to try and deal with the insurance company, they will never be helpful. You don't have to file a suit, but you should let the attorney handle the grunt work or at least direct you on the best course of action. Most good attorneys will tell you how to handle something and tell you that if it gets to a certain point then come back to them and they will handle it.
The US Supreme Court recently ruled against grandparents' rights. The reasoning being that grandparents do not have the right to interfere with the parents' parenting style.
A grandparent may, however, get visitation under certain circumstances: If one of the parents have died or is in prison, or if there is a divorce and there was a special relationship between the child and the grandparent before the divorce.