What You Perceive as a Blockage is Actually a Denial of Permission

You've probably seen it before. A person in front of stairs hesitating even though their legs know how to climb. An athlete missing a step they have mastered. A child refusing a threshold they cross every day. A patient unable to complete a movement their tests allow.

The strength is there, the flexibility is proper, the movement has been done a thousand times. Something still blocks it.

The word of the day: the perception → action loop

This is our first RNP glossary term. The perception → action loop is the constant back-and-forth between what your body perceives of the world (through the eyes, the inner ear that detects balance, the soles of the feet, the muscles themselves) and the movement it produces in response.

The movement modifies what you perceive, and what you perceive changes the next movement. It's a loop, never a one-way trip.

This loop is controlled by a brain that doesn't work as we think. The brain does not correct a movement during its execution, it doesn't have the time.

The information returning from the body (proprioception, the sense of the body in space that allows you to touch your nose with your eyes closed) takes one hundred to two hundred milliseconds to come back (Shadmehr 2010, Friston 2011, Neuron).

A sprinter places their foot on the ground in one hundred milliseconds. The feedback from this step would arrive too late, after the foot has already moved on.

The brain therefore predicts a future state of the body, and short circuits in the spinal cord (spinal loops, connections that do not pass through the brain to react faster) execute this prediction.

If the prediction is good, it's called fluidity, technique, ease.

If it falters, it becomes stiffness, a fall, hesitation, a movement that doesn't happen.

The architecture of authorization

Here's the practical key. The cortex (the thinking layer on the surface, where your conscious decisions are formed) decides. The brainstem (the part at the very bottom of the brain, just above the neck, which manages posture, balance, and vital functions) prepares. And it's a precise network of neurons inside the brainstem, the PRF (Pontine Reticular Formation), that ultimately authorizes the movement.

This is not an image, it's a documented neurological organization (Peterson 1979, Garcia-Rill 2015).

The PRF continuously reads the state of the body: safety or threat, fatigue, balance, presence of a residual reflex (a baby automatism that sometimes remains active in adults, like the ATNR which still couples head rotation with the arm).

When this state is not good, it locks the precise commands to the muscles fifty milliseconds before the intended movement. Not by choice. By architecture.

That's why you can have everything in place and still not succeed. And it's also why a few seconds of preparation can change what the body allows.

Three simple steps: see what is really there, choose the movement compatible with the current state, let the anticipatory reflex stability (the deep muscles that contract just before the movement to stabilize) activate fifty to ninety milliseconds before the action (Maffei et al. 2017).

Whether you are supporting athletes, patients in a clinic, children, the elderly, or seeking this framework for yourself, the RNP Lab has built an introduction that sets this paradigm and shows how it is implemented in reality.

👉 Discover here, it's free!