While I have not studied boxing, I thought that the Jack Dempsey drop (or falling) step probably was adding the energy of the ground reaction force from the front foot landing into his boxing technique – but I could be wrong. Of course, all of the torque, shifting of mass forward, extension of the arm, etc. also all contribute to the power of the punch. I am just looking for that extra thing (the “rebound”?) that allows power even with shorter distances (less windup...). Most sports seem to use their front foot primarily as a pivot for generating torque, rather than adding the ground reaction force to their power through direct transmission through the body as illustrated by the Newton’s cradle toy (i.e., not needing torque to transmit the force). Perhaps it is too difficult to see since all of the other aspects of power generation are still present (torque, moving the mass forward, pushing off from the rear foot, extension, kinetic chain...), or perhaps I am just imagining this type of power transfer (like that shown with the Newton’s cradle toy) when I practice this way.
Here are a few things to consider, however, from the short article about the research involving Chen Xiang. During his first visit they measured the amount of force that Chen could produce:
This level of force “astonished Rose and her students.” Presumably this means that more force was produced that for typical a person of his weight (although fighters of any other styles were not given comparative values for the power of their strikes). This probably means that Chen was either better at using the conventional power development methods (e.g., kinetic chain) than other strikers, or it means that he was generating some of his force in a different manner than other strikers.
Most seem to try to explain Chen’s force production using conventional terminology. For example, the robotics professor uses the data to “confirm his theory that these types of spiral movements may be a particularly efficient way to generate force in a small sphere of space.” Small spiral movements MAY be more efficient at developing power, but he ignores the possibility of the power coming from a different than conventional mechanism (i.e., the ground reaction force from the front foot being transmitted in a manner other than through spiraling torque).
There are several possibilities that I can think of:
1. Chen is so skilled that he can generate greater than expected power DESPITE generating it in a small sphere of space.
2. Chen generates greater than expected power BECAUSE he is generating it in a small sphere of space (using spiral movements).
3. Chen generates greater than expected power in a small sphere of space by adding a DIFFERENT mechanism (in addition to the spiral movements).
3A. This mechanism could have something to do with the ground reaction force with the front foot.
3B. It is due to qi/chi [note that the article does also mention this as a possibility, although they also recognize that qi/chi lacks an accurate definition].
4. Something else that I did not think of?
I think it is #3A. What do you think?
Although the researchers describe their results using conventional terminology, their decision to collect data from the front foot and its force to the ground (a force plate on the floor) provides supporting evidence for #3A. However, fighters of any other styles were not given comparative values for the front foot reacting with the floor, so it is difficult to know how Chen compares with others, so I do not know how unusual this may be.