snap kick uses

[Montana]

If a person has you in a good trap/hold of your leg in the scenerio you've described, your hands are being occupied by holding your face off the ground and the "trapper" is in a perfect position to kick your face and torso at will, or knee your lower abdomin/groin at will, and if he's strong enough, spin you around and slam your head into something (wall, pole, etc) pretty darn easily, and there's little you can do about it. Trying to bring your other leg to bear and attack his head with it isn't really much of an option. You might be able to push kick his torso, but you won't have much power behind your kick, and you would have only a very short amount of time to do this before he can do very serious damage to you.

Your best bet is to curl up towards his legs and grab his legs with your arms and try to take him to the ground, or to at least make him let you go.