I have a friend who has had a fall onto a concrete floor some six months ago. His lower back is very sore most of the time. He has seen a neurologist who after testing the friend, stated that the nerves are undamaged. The friend has a large amount of muscle wastage on his right leg, while the left leg remains normal and works well. The right leg however only has the top muscle of the thigh working while the remainder of the muscles will not work. The neurologist states that the femoral artery and nerve are okay, however they cannot explain the wasting of the muscles. What could be causing this?