Wack injury.

ok, on march break i was on a trip out west and i was skiing at kimberly. i didn't look at the jump before, but judging by all the others i assumed it was fairly large. it was the very first jump in the park and i went at it with a fair amount of speed to jusst 180 it. it popped me all wack and i over-shot it. i came down hard hit my head, blew out of my skis and winded myself. i lyed there for a while and soon after got up, and as i did so, i felt a sharp pain in my groin. after i skiid down the hill the pain got worse and worse. so once i got to the bottom of the hill i couldnt walk and had to be carried inside. so what im wondering is, how did i manage to rip my groin by just landing hard without spreading my legs or whatever. if anyone knows the answer, i'd gladly like to know.