The samurai is making a backhanded strike to the leg. The european has blocked it, and then spins the samurai around with an elbow to the back of the samurai's arm.
There are dozens of variations on this theme.....This is the responce to the number four attack. (That is the back hand to the leg). It works just fine for a number two or even an overhead strike which you meet with a crosswise lift of the sword and a brisk step to the left.
Note if you will that Talhoffer wanted to just push the opponents arm around with the hand...we assume that if you have a shield, you may not be able to do that as easily. We like to bump into people with the backs of our hands if at all possible. In the pictures above, you can see that we place our hands on the opponent's shoulder, then drop our elbow to catch his arm under the tricep.
Practice this a few times. It is a very handy movement.
- (fol 18r) Jung Ritter lere / got lip haben frawen io ere / So wechst dein ere / Uebe ritterschaft und lere / kunst dy dich zyret und in krigen sere hofiret
- "Young knight, learn to love God and revere noble ladies, so that your honour grows. Practice knighthood and learn the art that dignifies you, and brings you honour in wars."