Ever wonder what made Bruce Lee so ninja? Most of us assume that it all came down to superior athletic ability and training, and a lot of it does. But a study published in the journal Cerebral Cortex suggests that the source of Lee’s force may also be somewhat neurological. Expert martial arts moves — especially Lee’s famous “one-inch punch” — may start with  a specific brain structure that only the most ninja of humans possess.

The mighty one-inch punch does not rely solely on a quick arm but rather on Lee’s entire body. Jessica Rose, a biomechanics researcher at Stanford University, told Popular Mechanics that the force behind the fist starts with Lee’s equally deadly legs.

“When watching the one-inch punch, you can see that his leading and trailing legs straighten with a rapid, explosive knee extension,” Rose says. The quick preceding leg movement allows Lee to torque his hips with more power, and the hip twist allows him to turn his upper body that much faster. The millisecond Lee is actually using his shoulder to throw his hand forward, the strength of multiple muscle groups is already engaged.

“Flicking his wrist just prior to impact may further increase the fist velocity,” Rose told Popular Mechanics. Rose explained that the fact that Lee pulls his hand back immediately after impact increases the force of the punch by decreasing impact time, launching the bad guys that much further through the dojo walls.

The process by which multiple muscle groups work in sequence is called “kinetic linking.” Combat sports that involve kicking and punching specifically emphasize kinetic linking, but this process is also present in baseball and golf.

The video below shows the oft-discussed pitching mechanics of San Francisco’s Tim Lincecum. Lincecum’s high leg kick precedes his technique of bending his back to transfer as much energy as possible into his throwing hand. Notice how long he waits before releasing the torque of his upper body and throwing the ball.

And below you can see how batter Miguel Cabrera’s first step with his left foot and allows him to gain massive torque that eventually drives energy into his hands once they connect with the ball.

While Lee’s one-inch punch and Licecum’s fast ball have a lot to do with superb muscular biomechanics, the structure of their brains plays a role here too. “Muscle fibers do not dictate coordination,” Rose said, “coordination and timing are essential factors behind movements like [Lee’s] one-inch punch.”

To see what differences lie in the brains of people who are able to pull off these feats and those who cannot, neuroscientist Ed Roberts compared active martial artists with similarly built and fit people who didn’t have martial arts ability. In the Cerebral Cortex study, Roberts took brain scans of these two groups, and what he found was that the force the karate punchers were able to deliver within a tight two-inch distance was directly correlated with a density of white matter in their supplementary motor cortex. White matter manages communication between brain cells and the supplementary motor cortex is the section of the brain that controls coordination between different muscle groups.

The altered level of white matter could be what’s allowing the karate athletes to synchronize their bodies for moves like the killer close-range punch. Luckily for emerging karate enthusiasts, the human brain’s neuroplasticity — the ability to rewire itself — means that with enough practice in the dojo, you could alter your own white matter, helping you pull of moves like Lee’s.

Featured Image: Johnson Lau