Do a flying kick!

You prepare a run-up from the wall of the stairwell. You're going to jump down the staircase and kick that zombie right in the face!

Wind rushes through your hair. Your clothes billow out. You coil your legs - and leap! The thrill of being mid-air, the excitement of the jump; time flows in slow-motion as you extend a leg, aiming squarely for the zombie's face.

POW!

To your astonishment, it actually works! Your foot connects with her face, and with the momentum, you springboard off of the zombified woman, gaining precious momentum toward the exit door. Making sure to bend your knees, you make a harm landing, barreling straight through the emergency door and out to freedom! You actually did it! Holy shit!