Tenchi Nage is also known as the Heaven and Earth throw due to the fact that in the throw, one hand will travel towards heaven while the other hand will travel to the earth. This set of movements provides the Nage with an opportunity to manipulate the center of mass of the uke and at the same time unbalance them with a minimum of effort.
In this first image we can see the initial set up to perform the Tenchi Nage throw. Both the Uke and the Nage are "centered" and stable in their stances, though the Uke has begun to lose his stability. One hand is moving up the Uke's body, but it is not opposing the force that the Uke is exerting towards the Nage. The Nage is merely moving in a direction perpendicular to that force in order to make it easier on himself. The other hand pulls the lower hand along with it, again not opposing the Uke's force, but reinforcing and harmonizing with it to work to the Nage's benefit. The combination of these two movements pulls one shoulder of the Uke forward while the other shoulder moves backward slightly. This moves the center of mass of the Uke out from his body to a point that is slightly behind and below him.
The second image shows the terminal movement of the Uke as he falls. His legs moved forward as they carried the momentum of his initial attack. His right arm also moved forward pulling his right shoulder with it whilst his left shoulder and arm did not move. This movement twisted his body around and moved his center of mass away from his "center." At this point the Nage can take advantage of the instability to apply a small amount of force to the Uke in a direction that he does not have any legs to support him, i.e. backwards and to the left. Like a stool with 2 legs, the Uke falls to the ground.
See the whole thing with this animated Gif.
Home - About - Basics - Kaiten Nage - Tenchi Nage - Timing and Breath - Nifty - Bibliography