What is Muscle Stimulation and Are There Differences In the Purpose?
Unfortunately most people refer to muscle stimulation as the amount of electrical energy needed to produce a muscle nerve reaction such as a muscle twitch. That may be fine if all one is trying to do is increase blood flow, or compress to move fluids away from the area such as an edematous limb.
Functional Outcome Is Important With Muscle Stimulation
In therapy and rehab. that is not sufficient as an answer. The physical therapists define muscle stimulation ( electrostimulation) as "functional electrical stimulation", abbreviated as FES. The distinction is in therapy, possibly following a stroke, one of the primary purposes of the intervention is to teach the patient a new way to achieve functionality in executing a simple act such as picking up a coffee cup. The patient needs to regain the ability to volitionally cause muscles to contract so they can grasp the cup in a manner consistent with achieving the desired result of picking up, tilting the cup, holding still until can drink, then putting back down. The muscle stimulator is the catalyst to bridge the brain to the muscle so the patient can slowly learn how to regain control.
Many muscles require a pulse width ( amount of time the electrical stimulation is on - measured in thousandths of a second ) , of 350 milliseconds. This is not the amount of energy exiting the unit but the amount of energy required at the nerve itself in order to achieve functional stimulation. This amount of energy also varies according to the placement of the nerve which includes factors such as fat content, hydration of the patient, and the size of the nerve itself. As an example less energy is generally needed near the fingers due to closeness of nerves to the surface, lack of excessive fat tissue around the nerve, and smaller target area. Contrast that with the nerve(s) at the thigh for the quadriceps. One has larger muscles, greater surface area, deeper penetration needed so the ability of the muscle stimulator must be greater in output and possibly wave form to achieve the desired quadriceps response compared to stimulating the nerves for the fingers.
When one is choosing a muscle stimulator all these factors have to be considered just to determine if the muscle stim. unit itself has sufficient energy to achieve the desired results. The output has to be sufficient to achieve the desired results. Many companies will claim they have a "muscle stimulator unit" but all it does is have sufficient energy to stimulate muscle nerves but totally lacks the control mechanisms to be applicable to the desired patient outcomes.
A muscle stimulator is not indicated for muscle pain.