What does it means when a turlte kicks its legs out?

It depends I guess. front leg or back leg? I have had a turtle for like 13 years and most of the time he is just kicking to remove loose skin that is bothering him. I do know that is you have a female that kicking their back legs can be a sign of laying eggs. either way I don't think that there is any reason to be alarmed. I hope this helps