A clean movement… with dirty perception

The movement is impeccable. You film it, you slow it down frame by frame: the trajectory is smooth, the angles are correct. And yet, as soon as speed increases, the environment becomes unpredictable or fatigue sets in, everything collapses: the timing slips and the "clean" athlete becomes clumsy.

You correct the movement, it improves for a while, then the problem comes back. This is what I wish I had understood much earlier: a movement can be perfect biomechanically and failing neuro-functionally, because the problem sits in the information that drives it.

The brain drives on information

The brain commands every movement from the sensory information it receives in real time. If the visual information is imprecise, delayed or poorly processed, the motor command suffers, whatever the technical quality of the movement.

Vision works as a decision filter: it tells you when to act, accelerate, brake or secure (the visual system in RNP). When it is poorly calibrated, the body does what it can, with poor-quality information.

The two visual pathways

The brain has two main visual pathways. The first, called ventral, answers the question "what?": it recognizes objects and shapes, slowly and consciously. The second, called dorsal, answers "where, when, how?": it guides movement through space, fast and without thinking.

When you have someone repeat an isolated movement in a calm environment, you mostly call on recognition. But as soon as the context turns chaotic, the action pathway has to take over, and if it has never been challenged, it is not ready: the clean movement collapses under constraint.

A case at a youth academy

A young handball player at a training academy has above-average physical qualities. His coach sums it up: "He is always late." Technically, everything is correct; but as soon as the game speeds up, he endures it instead of reading it.

The RNP reflex was to test information intake before changing anything: saccades, smooth pursuit, the vestibulo-ocular reflex (what is the VOR). The saccades to the left were too short and the pursuit was unstable in the periphery. The work then focused on these functions, alongside the usual training, with regular retesting of saccades and pursuit.

One case, one person: it promises nothing for the next one, but it shows where to look.

Before asking whether the movement is correct, ask whether the information driving it is reliable.

To see how RNP, Neuro-Postural Reprogramming, links vision, coordination and timing, the coordination guide is free.

You are a practitioner and want to know whether the training is right for you: book a call with the team.

This gap between a clean movement and what the athlete has really learned is the subject of the article sensorimotor loop: the definition that changes the way you coach, on the RK Sport Performance blog.