I was training with Christian (8th Kyu) and working on deflecting his oncoming strike and then applying an upper block to the underside of his arm (see Dan-gun: Defence Against Front Kick and Punch Combo.) I would do it once or twice and I would let him strike me several times. As the drill progressed, I would increase striking force on the oncoming arm at various parts. Namely PC2, HT2, and TH12. I did several other techniques like elbowing him in GB23, and also grabbed the skinfold over his pectoral muscles for good effect.
Applying the Upper Block
There is a stipulated angle for the upper block and you see variants of this in all the nice karate or taekwondo pictures on the net. What is not discussed is how the upper block gets there. In our school, we practice two different ways of performing the upper block: you can do a vertical punch upwards and then rotate the elbow around into the upper block or you can swing it in one motion from it folder from the side into it straight ahead of you. Allowing the arm to freely swing without institutionalising movement allows me to 'apply' the block dependent on what I want to do with it.
To say that the upper block is one way and not the other is to reduce the value of it as a taekwondo technique. Today we saw how to apply this chukyo marki upper block to the arm at shoulder level or neck level. Where you apply the force - meaning, striking with the forearm, or elbow, or fist ... is up to you.
Dan-gun: Is a Block Just a Block?
Dan-gun: Defensive Drills Against Strikes
Dan-gun: Windshield Wiping Technique
Black Belt Coaching Course
Martial Arts Grading Oral Section
Do-san: Rising Block or Chukyo Marki or Age Uke
Upper Block, Chukyo Marki, or Age Uke
Taekwondo Techniques, Patterns, and Applications at the Traditional Taekwondo Blog.