I have the same problem in a muscle wich is near the hip... dont know how the fuck its called but it clicks and sometimes it hurt's like shit... I went to doctor and he told it was a pulled muscle.... but it has been 1 month since then and it keeps annoying me! its a completly shit!! and the doctor surely is a shiit too!! FUCK HIM! 
dude you pulled you hip flexor (thats what it's called)....stretch it sometimes, but you have to rest it a bit
it takes a while to heal
Yes I know how the muscle is called in spanish... but dunno in english...
in spanish its called: el sogas.... wich maybe is the hip flexor in english...
and im stretching alot before freestyling, more than the other muscles...but it still click's when im doing atw's... I cant even do a latw because last time I did it, it hurt like shiit!!so I think if I do latw again it will pull again...
anyways, thanks for the help man!