I had the exact same injury in 2010. Touched wheels and went down on the left shoulder. Was able to ride home, very little pain. Went to emergency, x-rays, sent home and told to see a orthopedist. Orthopedist said I can have surgery or not, either way, it'll be fine. Elected not to have surgery. Except for a bump from the end of the collarbone which surgery would have fixed, no problems at all in flexibility or lifting. It took a few weeks for full arm strength to return.