Physics and martial arts theory intersect at the concept of force transfer: how kinetic energy from one body transmits to another through collision. Traditional combat training emphasizes direct impact—one fighter striking an opponent directly. Yet advanced technique theory proposes secondary-target force transfer: using a nearby object or person as a vector to transmit force toward a distant target. This violates intuitive physics and suggests a level of precision control difficult to achieve.

Marcus Fontaine, a Brazilian jiu-jitsu instructor in Sacramento, trained professional fighters throughout the 1990s and documented an extraordinary incident in his private journals. He described observing a consultant deliver what he termed a 'redirected force strike': impact delivered against an unintended third party that nonetheless resulted in fatal injury to another person standing at a distance. Fontaine's notes state: 'I observed one man rotate his leg horizontally, contact a bystander on the side of his face, and a separate target twelve feet distant collapsed as if struck directly. Physics doesn't explain this. Neither does anatomy.'

Fontaine never published these observations and shifted his teaching focus entirely away from striking techniques. When questioned by colleagues, he stated: 'Some people control force with such precision that the laws of impact physics seem optional. I don't want to understand it more deeply than I already do. It frightens me.'