Burning/catching pain in shoulder..please help!!!!!

I have had a problem with my shoulder for almost a year now. The first time i hurt my shoulder was when i landed on an outstretched arm. After this i had trouble in lifting my arm over my head and out from the side. I decided to rest the shoulder, and let it heal over time. After around four months i did not get any trouble with the shoulder. Since then, i have had problems with the same shoulder four times, each time the symptoms lasting a month or two. The pain i experience is a constant dull ache and i get a catching/popping sensation when trying to lift the arm. I also sometimes get this burning sensation which can be very painful. I was wondering if there is anyone out there who might be able to tell me what they think i might have done, and how to go about treating this problem, as it’s really annoying how it always reoccurs. Is it possible something has been torn, or could it just be a case of tendernitis?.