I injured my shoulder one month ago and it hasn't gotten better. I have no strength picking objects up when my arm remains extended. I can't resist the weight of someone else's push on my arm while it is extended forward. The range of motion has gotten better, but I still find it difficult to reach my back over my head, and to reach it under my head behind my back. I only feel pain in it when lifting objects. It feels like a sharp nerve pain in the front part of my shoulder that goes a little further down my arm.