Now to be sure, when we sing lower pitches, there is a feel of being down and in front or “forward” due to more mass of the cords vibrating to create those lower pitches.
However, as we sing higher and there is less chordal vibration, we get the feel of moving up and back.
If we try to maintain the “forward” feel of the lower pitches as we ascend the scale, then we are violating the laws of physics. We are not allowing the cords to adjust for the higher pitches. We are in effect keeping the cords too thick, and this leads to: