"Why does it always come back?"

"Why does it always come back?"

It is the question you hear most among physiotherapists and osteopaths.

At seminars, it almost always comes up on the first day, at the break, when we talk about concrete cases. A person comes back with the same complaint three weeks after a session that went very well, and the practitioner wonders what they missed.

The explanations we give ourselves then all sound alike:

• the person didn't do their exercises

• I didn't insist enough on the correction

• that's just how their body is, it will always come back

None of them looks in the right place.

To understand, we need to talk about motor decision. It is the choice your nervous system makes, just before a movement, about how to perform it, based on what it perceives of the environment, of balance and of the body (the full definition is here).

This choice is made before the movement, and largely before you are aware of having chosen. In the 1980s, Benjamin Libet measured electrical activity in the brain that builds up several hundred milliseconds before the moment the person says they decided. What exactly this signal means is still debated, since Aaron Schurger's work in 2012, but one point is consensual: preparation of the movement begins before we are aware of it.

The body also prepares the movement physically. When you raise an arm on a signal, the muscles at the back of the thigh activate a few dozen milliseconds before the shoulder, to anchor the body to the ground ahead of the loss of balance. And this preparation adapts: when the movement is self-initiated, it precedes the movement; on a "go" signal, it shrinks and becomes simultaneous, because the system chooses to start faster rather than more stable.

The image that helped me most to understand why a movement comes back comes from space. Astronauts kept these postural preparation programs after two weeks in weightlessness, even though there was no longer any balance to protect (work by Massion and Berthoz). What comes back most readily are these old, deeply installed settings.

Movement researchers have a word for that: an attractor. It is the way of moving that the body falls back into on its own, especially when things go fast or when it is tired, like a marble that always rolls back to the bottom of a bowl.

A verbal correction, for its part, goes through attention: "keep the knee in line", "relax the shoulder", "breathe low". In the clinic, in calm conditions, attention holds and the corrected movement holds with it. As soon as the person gets back to their life, their fatigue, their stairs and their overly long days, attention lets go first, and the marble rolls back to the bottom of the bowl.

That is where the complaint comes back. The movement comes back because the decision that produces it was never touched, much more than for lack of willpower. Often, what we see is a compensation, that is, a fallback solution that works around missing information instead of fixing it, and that holds only as long as nobody puts it under pressure.

For a long time I believed that explaining better would be enough. It took me years to accept that my most beautiful corrections in session were sometimes the ones that held the least.

Here are three tests to know where you stand with the person you have in mind:

• three repetitions in calm conditions with your usual cue

• three repetitions at real speed or fatigued, without saying anything

• compare the two, and note what comes undone

If the movement holds under constraint, it was a question of intention, and your cue did the job. If it comes undone as soon as you go quiet or things speed up, look at what the system perceives, not at technique.

To go further, film the failed repetition and the successful one with your phone's slow-motion mode, at 120 or 240 frames per second. Stop just before the start and note three signs: where the gaze goes, whether the pelvis tips, how the foot contact is prepared. In normal video, three tenths of a second is only nine frames: that is too few to see anything.

Last test, the most telling: change a single input, without talking about the movement. It could be the point the gaze fixes on, the surface under the feet or the position of the head, then you redo the three repetitions without a cue. If the fault changes on its own, the motor decision lead holds; if it doesn't budge even though the input really changed, look elsewhere.

This is exactly the logic of RNP, in three steps. Read where it's dark: which sensor drops out, on which side, and in which situation. Switch it back on: stimulate that precise input, then retest, following the test, stimulation, retest protocol. Make it hold: check that the result survives speed, fatigue and your absence, before considering it acquired.

What I take from it is that the fault that comes back is not stubborn at all: it is filed further upstream than the place where we correct it.

What always comes back is what was never read.

If you want to see what happens in this window that precedes the movement, we devoted a whole article to it, with what you can observe by eye. Two other readings go in the same direction: what really triggers a technique, and why correcting too fast switches off learning.

If this kind of reading speaks to you, come and take a closer look: we have already trained more than 1,000 practitioners, across 12 professions. You're a practitioner: the introduction to RNP, Neuro-Postural Reprogramming, is free, as is the "How we learn to move" course. You're looking for support: request an assessment.