In the lower bind, a strong key, I have held you in such a way that you cannot escape, no matter how strong you are. Trouble and death I can give you. I could write a letter that you could not see. You have no sword, no helmet, small honour and little to celebrate.
The 5th scholar of the sword in armour continues directly from the 4th scholar. The two plays essentially show the start and finish of the same technique.
From the master play, step through with your left foot and roll your opponents sword over to your right. You will land in the position shown by the 1st scholar. Release your left hand from your sword and lunge forward. Slide your hand over your opponents right forearm and then up behind their arm to the back of their shoulder as shown by the 4th scholar.
Pivot on the left foot and arc your right foot around 180 degrees. Use your hips to shove into your opponents space. It is important to be right on top of them. Lock your left elbow tight against your body and lever your opponent down as shown.
To hold your opponent in place long enough to write a letter explaining how bad they are, you will need to keep your hips pressed tight against their body. The closer you can move up to their armpit, the greater your mechanical advantage will be. Your opponents hand should be pressed against their spine, while you push down on their shoulder.
If you look at the master play, 1st scholar, 4th scholar and 5th scholar, they make a nice cartoon strip of entering into narrow play and applying a lower bind. Once achieved, you can stab, strike or hold your opponent as desired.