What is the best treatment for ulna nerve impingement?

Take off pressure. I'm assuming you have numbness in your ring and small fingers from ulnar neuropathy. Most often, this is caused by resting the forearm on a desk/table edge or armrest on a chair or in a car. Simply remove your arm from ever resting weight on these places, and the problem should resolve. If it doesn't, then the worst case scenario is that an orthopedist may need to reposition the nerve.