while performing these exercises the patient must inhibit any type of voluntary contraction and must limit himself to adapting the muscle tone of the limb in such a way as to allow the physiotherapist to guide its movement.

“In some of these exercises, after showing the patient a series of pictures, his hand is guided, inhibiting any voluntary contraction, to follow the contours of the figures themselves with their eyes closed and then the patient is asked to identify on which figure in the series the arm has been guided2.”. To be able to perform this exercise correctly the patient will have to:

• perform a visual analysis of the figures that are shown to him.
• transform the visual angles of the contours of the figures into kinesthetic angles or into an idea / hypothesis of the movement that his limb will have to make to follow the different contours of the figures themselves (perceptual hypothesis).
• carry out an analysis of the movements that the physiotherapist is making his limb perform (kinesthetic analysis), to make him follow the contours of the figures. This movement analysis is based solely on proprioceptive information.
• Compare the kinesthetic analysis of movement perceived through proprioception with the idea / hypothesis of movement that he had created based on the vision of the image contours (verification of the perceptual hypothesis).

2nd degree exercises

In these exercises, which aim at the irradiation control, "The patient is asked to verify perceptual hypotheses that require the recruitment of only a few motor units of a small number of muscles (..)3”. This type of exercise is essential to bring the patient to “control over the radiated contractions determined by the movement voluntarily performed4.”. To perform this exercise correctly, the patient will have to learn to modulate muscle recruitment to perform a kinesthetic analysis by actively moving the limb in order to then be able to verify the perceptual hypotheses. In 1st degree exercises this movement was guided entirely by the physiotherapist. In the 2nd degree exercises actually the patient actively performs only part of the entire trajectory of movement, which takes place in any case with the facilitation of the therapist's manual guidance who must measure their intervention by evaluating how much of the movement to actively allow the patient to perform based on the patient's ability to control the irradiation. The therapist, as well as calibrating the facilitation, he must also carefully measure the speed with which the movement is made, bearing in mind that one of the factors that trigger irradiation is the speed of movements. All first degree exercises can be transformed into second degree exercises.

3rd degree exercises

They serve to help the patient carry out a process of generalization of the trajectories performed with the first and second degree exercises to allow him the possibility of executing as many trajectories as possible and in the most functional way possible "using information from the outside and from his own body only to regulate spatiality, temporality and intensity of the movement, as does the healthy subject, when he has to learn a new motor performance5.”. It is possible to propose this type of exercise to the patient only when he has come to control in an automated way (subcortical), through first and second degree exercises, irradiation and the reaction to stretching. The automatic control of these two parameters allows the patient to focus exclusively on the evaluation of any discrepancies between the movement trajectory requested by the physiotherapist and the one he performed..

Voluntary control (cortical) and automatic control (subcortical).

In the exercises of 1st and 2nd we assist, as we have seen, to a transition from a voluntary control of irradiation (1st exercises) and the abnormal reaction to stretching (2nd exercises) to an automatic control.

In reality, even the learning of new motor skills in physiological conditions takes place through a transition from a first phase that takes place through voluntary control (cortical) of the execution of the motor task to be learned in a second phase in which the control of the activity we carry out takes place in an "automated" way (subcortical).

When we learn to bring the car we have to pay attention in a controlled way to how to put our foot down to brake, to accelerate, how much force should we use to push the pedal, the direction in which to move the shift lever to change gears, how far we have to turn the steering wheel and in what precise sequence we have to carry out all these individual actions necessary to carry on driving. And at the beginning it is very difficult and often the car switches off because we don't know how to adjust the clutch and accelerator. When we have finished the learning process, we carry out all these actions automatically without having to pay attention and we can chat with passengers while we think about the route to choose to get to the desired destination..