Over the hill and still (thankfully) injury free...
Maybe you should consider a very thorough warmup routine for your shoulder in addition to a flexy paddle. Obviously, don't jump back in there until everything is healed. I carry a 5' long piece of latex surgical tubing with me in my gear bag, tie it around a tree and give my shoulders a good ol' workout before even jumping in my boat. It's funny 'cause the older I get, the more I want to paddle, yet the more I've got to be careful about getting hurt. Somedays it takes me an hour to stretch and warm up and hydrate before jumping in the playhole -- but I can usually keep up with punks half my age.