ultimate frisbee

OB1 was having one of their Friday night sporting get-togethers. Ultimate frisbee was the activity. I knew I didn't want to play because of my back, but I went just to see friends. Unfortunately, I couldn't resist picking up the frisbee and giving it a heave on a "kick-off" situation. I felt something wrench, and I'm pretty sure I threw my back out somewhat. Ouch!