I am an engineer dealing with Brain-Computer Interface, and at the moment, in a clinical context. One area which I came across was rehabilitation for patients suffering from Spinal Cord Injuries or stroke patients and that one method, is to artificially excite the paralyzed muscle to trigger movement. This is supposed to restore some of the lost functionality of the reduced motor functions.
My question is this:
If this method is used to increase activation in motor functions, how does stimulating neurons on the muscle result in such a thing? from my understanding, the sensory signals go from the limbs/body parts to the brain, and bio-signals that move the muscles are fired from brain, through the spinal chord and to the targeted muscle, so how does activation of these neurons near the muscle help restore brain's motor function firing mechanism?
So if the motor functions are reduced in SCI patients, would the non-motor functions leading to those motor functions to be created also be decreased too? From my understanding, before the motor function is created, certain neurons in certain brain cortices are fired, which result in these neural functions.