Koshi Nage in Aikido - “Hip Throw”
This technique is among the more advanced and requires a higher level of taking Ukemi from the partner as well to avoid injuries.
Koshi Nage, or “Hip Throw”, focuses upon the movement of your waist and hips as Uke is being lifted from the ground. It uses a man's hips as the fulcrum of removal and rotation of another man's body in an effort to project him down onto the ground. In aikido practice, we find many technical and dynamic applications of this type of technique in response to almost all of the basic types of attack.
The fundamental characteristics of this projection (in relation to the use of your hips at the moment when Uke is about to be lifted from the ground) are generally related to the positioning of your hips against and across his lower abdomen as you establish an axis or fulcrum around which his body will have to rotate. In flight he will be turned upside down and will hit the mat reversed, on his back. This positioning is, first, markedly lateral in the sense that you will bring your side into contact with the frontal side of his lower abdomen, with the axis of your body cutting diagonally across the axis of his body. It is important that you do not cause his upper body to lean unbalanced over your upper trunk, because your main centre of support will be much lower, i.e., the powerfully articulated structure of your hips and pelvic area.
Second, your lower abdomen must be lower than his because you will not be attempting to lift him muscularly, but rather causing his body to lean almost naturally and effortlessly upon your lowered hips. You will then be able to roll him easily around, over, and down to the mat. You must, therefore, sink low, bending your knees well to prepare for the rotation of Uke over your lowered hips – this rotation, of course, being only preliminary to his fall onto the mat, flat on his back.