Thank you. How would you describe the differences in forms from one tkd style to another in your experience?
The form sets are more similar than dis- really. They all cover essentially the same movements, But strung together in different orders. the KKW Taegeuk forms are designed to be more readily learned by younger students. This is in keeping with the KKW philosophy that 1st Dan is a beginner rank and can be awarded very quickly, with a year not being uncommon.
There are subtle differences in the movements, but to a layperson or someone without a fair bit of experience, the movements seem the same. Some examples...
The MDK front stance is long, wide, and deep, much as it is done in the Shotokan that provided the basis for much of TKD. The KKW front stance is much shorter, more narrow, and more upright.
The MDK and KKW back stance are done with about 75% of the weight on the rear leg. The ITF is more centered.
The MDK and KKW teach roundhouse kicks (initially) striking with the arch of the foot, and with the ball of the foot later. The ITF calls it a turning kick and starts with the ball of the foot.
Stepping in the MDK and KKW is done while keeping the head essentially at the same height. The ITF standard includes sine wave movement, basically rising up and dropping back down as a way to generate power. I'm not convinced it does anything, and I learned the ITF curriculum before sine wave was really a thing. I don't teach it. And lots of ITF off-shoots that still use the Chang Hon forms do not.
Along that same line, how would you describe the differences between those styles themselves, and do those Differences drive the differences in the forms?
To be brutally honest, many of the differences are strictly political. Tang Soo Do and Soo Bahk Do exist only because GM HWANG, Kee got upset that he wasn't elected to head the KTA and left. He took about 1/3 of the Moo Duk Kwan with him. And since General Choi passed, how many branches of the ITF have been birthed? There are at least three totally different orgs that claim to be
the ITF.
The other differences are, I think, primarily the result of different founders views on what should be stressed, e.g. the ball of the foot vs arch of the foot.
In my experience, it's really very easy for a person to change styles of TKD. When I decided to add KKW rank (because we offer it as an option) I spent a couple of weeks learning the Taegeuk forms and then tested with a KKW 4th and 6th Dan. The Yudanja forms for the KKW and our branch of the MDK are the same, except for when you learn them. In the KKW, you learn Koryo as a 1st Dan. In our MDK, you learn it as a 1st Geup.