Inner tubing at Bull Shoals with venturing crew. Windy, rainy, lots of waves. On a 2-person tube and my arm got jerked as we bounced over waves.
I took Advil every 4 hours until I went to bed, and I iced it on the long ride home. I can stretch it a little with my other hand if I keep it relaxed, and I can carry stuff around as long as I bend my arm at the elbow and not the shoulder. Felt more flexible the 2nd morning, and washing my hair in a hot shower wasn't painful.