Why can we, without looking, say, at the fingers of our hands, say what position they are in: straightened, half-bent or clenched into a fist? Because the muscles and joints in the brain constantly receive so-called proprioceptive impulses, “telling” about what is happening on the “periphery of the body”. In this way, the brain receives information about the state of the musculoskeletal system and, in turn, determines its activity, sending impulses to the muscles and joints, which, having received them, begin to follow the “instructions” of the brain.
Nature created us in such a way that when our brain is excited, the skeletal muscles involuntarily tense up and become more enslaved, the stronger the mental excitement. All athletes who are prone to prelaunch fever are well aware of this from their own sad experience when, due to excessive excitement, the muscles become “clamped”, losing speed and precision of movements.This happens because in the state of arousal the brain sends much more impulses to the “periphery of the body” (in particular, to the muscles) than at rest. Conversely, the calmer a person is, the more relaxed his skeletal muscles become. And they also relax involuntarily , because now they receive very few stimuli from the calm brain. Remember how an annoyed and serenely sleeping person looks different. At the first all muscles are tense, at the second – extremely relaxed.
The connection between the brain and skeletal muscles, as already mentioned, is bilateral: not only the nervous system determines the muscle tone, but also the muscles affect the state of the nervous system. Biological impulses entering the brain from the musculoskeletal system, not only carry information about the state of the “periphery of the body”, but also are peculiar stimuli thatstimulate brain activity, stimulating it. The more intense, more active the muscles, the more naturally the proprioceptive impulses come from them to the brain, the more it is activated. So, in particular, during morning exercises, as a result of physical exercises, the brain, which has calmed down and rested during the night, becomes active. The same effect gives an active warm-up: loading, straining, relaxing, warming the muscles and joints, that is, preparing them to work, athletes at the same time increase their mental tone before workouts and competitions.
The opposite picture is observed with conscious relaxation of skeletal muscles: the more relaxed they are, the less proprioceptive impulses come from them to the brain. And when the brain receives less and less stimulating signals from the “periphery of the body,” it begins to calm down , plunging first into a state of passive wakefulness, then into drowsiness, and finally into deep sleep.
This simple physiological pattern is used in the PMT for the conscious achievement of a drowsy state and control over it. Therefore, in order to enter the state of drowsiness that is controlled by consciousness, it is necessary to learn how to relax the skeletal muscles to the extent that this state causes. This is the way to mastering the first main mechanism of self-suggestion. But in order to relax your muscles well, you need to be able to “see” this process, to mentally represent it.