the string got tangled without my knowing about 3 inches in, and seeing as it was short it still had all the momentum of when I had given it a good throw. swung and hit my other hand. hurt so much.
At school few months ago it was like 10minutes before class started, i was throwing my code 2 which had a snag reeally hard and it came and hit my lip super hard that my teeth cut into my lip. Had to go the whole day with a swollen bloody lip. :-[
Funny how the worst injury I got was a counterweight to the groin :-\
I ha the same thing happen to me.
learning air binds may of been the most painful time everā¦ also ive hit my nuckles and fingers really hard too many times to count. ive even broken nails pretty bad before. Its just what we do 
Nasty string burn before I got into string making.
http://farm3.staticflickr.com/2250/3596732897_4c9c19c05e_z.jpg
String Burn by MBsShots, on Flickr
Letās just say Iāve had my fair share of E.R trips due to yoyos! Lol.
Nothing as serious as some of the stories here. Guess Iāve been lucky so farā¦
Worst personal injury was getting a large bruise in the base of my index finger from catching yoyoās that are returning too hard.
Worst injury I know of was twirling a yoyo over my head like a lasso when I was 7 and whacking my cousin on the head. She still brings that up sometimesā¦ 
My worst was my NVx was knoted around itself and i set it down for a few days. Pick it and forgetting about the knot and went to throw a break away where it hit me right to the side of my head.
thats the worst! i hate that! it scares me so much. ill get a knot and set it down and when i pick it up to throw i forget its knoted and it scares me hahaha
Whenever I get a knot around the bearing and donāt feel like taking it out. I take the yoyo off of my finger and place it unwound on my dresser so that I know thereās a knot the next time I use that yoyo.
Well it wasnāt the worst but that happened to me too. I also got hit above my eye with my L3 and it hurt for awhile after that.
i know a guy who broehis eyebrow!
Is that recent??!
Funny I found this thread today. Today I failed a trick and hit myself on the forehead just hurt for a bit. Thought I should share. Happy yoyoing!
dang i feel lucky now hahah i havent got hit like that hahaha
holy crap u got messed up hhahahaha.
Edit
i watched the whole vid. iv hit myself in the eye but thats crazy!!!