There are two criteria to determine where the angle of falling begins. Until these two criteria are met, the runner is moving forward primarily by momentum.
- The runner is in the Pose,
- The runner's heel is off the ground.
An obvious question is how does one determine where the angle of falling ends? The answer is that is that it ends when the runner breaks the Pose.
It is important to realize that the maximum angle a runner can reach is 22.5 degrees from a line perpendicular to the ground. The more of that angle is taken up by momentum, the less of the angle can be used for acceleration.