Can Back Muscle Pain Caused By Injury Need Treatment?

hi about 3 weeks ago i fell on my stairs and hit my back pretty hard on my right side about half way between my neck and waist around my first rib. There was no bruise. It hurt really bad for the first few days but then somewhat subsided, but it still hurts when i do anything using the muscles in that area. For example i opened the dumpster at work tonight and got a searing pain in my right side back muscle. I am afraid i have permanent muscle damage