We got to e-stim ourselves today in lab, which is a very weird feeling, but an extremely useful clinical tool.
It is a low-level electrical stimulation to the motor neurons to facilitate a muscle contraction. It is esp good if you have had a stroke (or have some other central nervous system condition impacting muscle function), when paired with a functional activity. It's basically telling the brain "hey this is an important pathway!" You see changes in the sensory-motor cortex from this, and it also strengthens that associated muscle.
Or, you can also use it to calm down an overactive muscle (spasticity). You stimulate the opposing muscle. There's sort of a loop in the nervous system so if one muscle is activated, it's opposing muscle (antagonist) becomes inhibited. It is called reciprocal inhibition. My understanding is that it can be difficult for patients with spasticity to activate the antagonist very strongly on their own just because they're sort of stuck in that pattern, but you can use functional electrical stimulation to disrupt the pattern and that overactive muscle relaxes.
Your kisses, sweeter than honey. But guess what, so is my money.