Please find below the source reference for the class:
This is the text and the gloss about running-through
Run-through, allow to hang
With the pommel, grasp if you wish to wrestle.
Whoever strengthens against you,
Note, this is when one runs-in to the other: if he then drives up with the arms and wishes to overwhelm you above with strength, so drive up as well with the arms, and hold your sword with the left hand near the pommel over your head and allow the blade to hang behind over your back, and run-through with your head under his right arm and spring with the right foot behind his right, and with the spring, drive him well forward with the right arm around the body, and clasp him thusly to the right hip and throw him in front of you (…)
This is yet another play about running-through
Item. when he wishes to overpower you with strength by running-in with the sword high: so hold your sword with the left hand near the pommel and let the blade hang over your back. Run-through with the head under his right arm, and remain with the right foot forward before his right and drive in well behind him with the right arm around the body, and clasp him upon your right hip and throw him behind you
Taken from the gloss (comments) of Sigmund ain Ringeck – 15th century German fencing master who is considered to be an author of the four original glosses of the Recital which makes him one of the most important masters of the Liechtenauer tradition.