股割り

Lit.: Groin stretch

Also sometimes called Kaikyaku, however this term isn't used very much, Matawari is the correct name.

Matawari is one of the Basic Sumou exercises. It is designed to develop flexibility in the hips. Hip flexibility is the key to Sumou performance. Since the object of a Shoubu is to push the opponent out of the ring, if you have a lower center of gravity, you can apply pushing pressure forward and up, thus slightly lifting the opponent and pushing him out at the same time. In order to be able to get low, you must be flexible. Therefore the Matawari...

Matawari demonstration movie

From a standing position squat down and slowly spread your legs to the side. Rest with your hands on the floor and spread the legs as much to the side as possible. Then slowly, while relaxing the leg muscles, not forcefully stretching them, try to bring your backside to the floor, sit down with legs stretched out. The object is to do a full split.

From this position, while relaxing the leg muscles, not forcefully stretching them, and breathing deeply, bring your chest forward. Don't bend your back, but keep it straight, instead tilt the pelvis forward. Bring your whole chest to the ground and spread your arms to the side.

Keep this position as long as possible. In practice at least for a couple of minutes.