Got caught in the rope...

On my last session for the season, I end up bailing and somehow got caught up in the rope. I'm using a basic surf rope from inland surfer. I'm not sure if it's because I was surfing backside with my heels to the wave (didn't feel like moving the sacks). Probably got dragged for 5-10 seconds before the crew saw me signaling to kill-it. Luckily I had a wetsuit top on so that prevented rope burn. The rope got caught up almost in my armpit. My tricep is bruised really bad and arm swollen purple down to my elbow. I think what happened is I sort of slapped the rope with my back arm as I went down and it looped around once and got caught at the handle. As soon as the boat stopped I slipped out easy but my arm was in some serious pain. Anyway just a heads up and maybe we can talk about some tips to prevent this from happening again.