Originally Posted by Anton Emery
Most other videos i have seen have the planting foot in between the legs, are they both just different ways to do it?
Uchi mata and I are like two friends that had an argument and never really made up. That aside, both the location of the plant foot and the target of the reaping foot can have some variation in placement based on (1) personal preference and (2) relative heights/leg lengths between you and your opponent.
The way I learned uchi mata was with a traditional inside foot placement: strong pull, cross stepping behind my reaping leg with a powerful stomp, then targeting either the near side or far side inner-thigh depending on opponents height and stance (or "up the middle" if you don't like uke).
However, one way I can see the value of the outside step is to think about the wonderful tai-otoshi to uchi mata combination. If you throw tai-o, your opponent steps over with his near leg, then he is in a very extended position (almost a forward lunge). Boom, uchi mata and I get along just great. In both Gant's intentional outside step + pull and the tai-o combination, you get great unweighting of the near-to-you leg.
In the first slow motion shot, you can see the wonderful timing of Gant's partner's forward step with his right foot just in time to become weighted and have the back leg start its take off.