The Inside Kick is a nice move for disrupting your opponents base and balance. Here, it is shown against a stationary opponent. It can also be used when your opponent steps forward to thro a punch or anymove that has him/her shift their weight forward.
Kai and I square off...
Kai steps out with his right foot 45 degrees to his right and shifts his weight to his right foot. Kai is careful to keep his hands up and eyes forward
Keeping his left leg bent but stiff, Kai swings his left shin into my left inner thigh. Kai drives his hips inward at the moment of impact.