Front push/thrust kick or Chudan mae-geri kekomi from a front leg of a back stance. Or if you prefer, starting from a front stance making a sliding rear leg (step up) into the mae-geri kekomi with the front leg. Q: Which do you following variations would or do you instruct your students to do: After chambering followed by striking with the heel of the foot, begin thrusting the hip, while simultaniously dropping the knee (thus straightening into full extension, making the leg horizontal from hip to target) with heel on target's middle section? The striking area of the foot (heel) being the same as a Chudan Yoko Geri Kekomi (sidekick) or alternately an instep stomp kick. Or thrusting the hip, while pushing a snapped kick into the target so that you are striking with the ball of the foot. (Snap a front kick, making a horizontal line between hip, ankle, and ball of the toe, using hip rotation and thrust to push into the target) This kick is a modified front snap kick. Foot chambering and return to back stance or cat stance, or even sliding back into the front stance.