15. Uchi-mata-sukashi 内股すかし

Uchi-mata-sukashi 内股すかし

Inside Thigh Slip Counter

Classification: Te-waza (Hand Technique)
Japanese meaning:

Uchi-mata = inner thigh
Sukashi = to slip or evade
This technique’s name reflects its purpose: evading the classic uchi-mata throw and using the opponent’s own motion to counter it.

Technical Description

Uchi-mata-sukashi is a counter throw executed when uke attempts an uchi-mata (inner thigh reap). Instead of resisting, tori evades by slipping slightly off-line, allowing uke’s reaping leg to miss. As uke becomes unbalanced due to the failed attack, tori uses a swift rotating motion of both arms to redirect uke’s momentum and throw them forward.

It’s a beautiful example of ju no ri—the principle of yielding—where tori avoids direct confrontation and instead takes advantage of uke’s over-commitment.

Biomechanics of Uchi-mata-sukashi

This is primarily a moment throw:

F1 and F2 (the arms) generate a torque (rotational force) to redirect uke’s forward and upward momentum.
The reaction force (Re) is used to extend uke’s movement beyond their center of gravity.
As uke’s leg sweeps upward for the uchi-mata, tori pivots slightly and rotates uke’s upper body in a circular arc, amplifying the centrifugal force and causing a forward fall.

Timing and sensitivity are crucial—tori must feel the opening the moment uke overextends.

Did You Know?

This technique is a textbook example of kaeshi-waza—counter techniques where tori turns uke’s attack against them.
It is especially effective against opponents who favour uchi-mata as their tokui-waza (favourite throw).
Uchi-mata-sukashi has been successfully used at the highest levels of judo, including IJF World Tour competitions.
In kata forms such as Kaeshi-no-kata and in high-level randori, this throw illustrates adaptive judo strategy at its best: don’t block—redirect.