Obviously, foot movement is something that comes up with every Judo beginner. In my very short amount of time doing Judo, the most common problem seems to be the tenkan step.
Let’s back up a second. The tenkan is a movement that is almost universal to Asian martial arts. You’ll recognize it best by example; if you’ve done Judo, the tenkan is the step you perform to enter tsukuri for a forward throw. Its that “step behind your foot” motion on uchi mata. If you’ve done Karate, Tae Kwon Do, Hapkido, or any other related art that does primary kicking attacks, the tenkan is the step you take to deliver a powerful roundhouse kick. In some ryu of Karate, it is also used for back-of-fist attacks.
So, to the point; because of simple bio-mechanics, the efficacy of your tenkan step – that is, the strength of your base, your ability to keep balance, et cetera and so on – will directly correlate to the power translations in your attack. If your tenkan is off balance or weak, your attack will have no drive. This is why judoka do that instinctive thing where, when practicing our entries, we’re slamming our foot into the ground – we are establishing, and testing our base.
I’ve been trying to think of ways to train this movement in isolation. The best thing I can come up with right now is a backpack loaded with rocks, carried high on the back. Thoughts?
Here is a link to the Wikipedia article on the tenkan for reference: https://en.wikipedia.org/wiki/Tenkan