Different parts of the body are more vital and fragile. Like in a real fight, a kick to the face hurts more than a kick to the shin. You'll gain more points if you hit something more vulnerable (e.g. Chest, Head, Neck) It also takes into consideration of how hard you hit that body part.

As of for EXACT points. I don't think there is, it's measured by the limb and power of your hit i think