A muscle stimulator is not the proper name for what this type device is

designed for.  The proper name is a Functional Electrical Stimulator or

FES unit for short.   Tens units are not muscle stimulators, tens units

are used for pain.  Muscle stim. units are used to regain function such

as post stroke rehabilitation, or to retard disuse atrophy, and in some

situations to reduce swelling and edema.

    Basically any electrical device, microamperage unit excluded, can be

powered up enough to stimulate motor, muscle, nerves.  That is a

function of the amount of energy necessary to "fire" a motor nerve.  

That is generally not the goal when one refers to muscle stimulation. 

It's very misleading for a tens machine distributor or manufacturer to

refer to their tens units as muscle stimulators.

   The purpose of a FES unit, functional electrical stimulator, is to

help a patient regain control of the major and minor muscle functions so

the patient can resume daily activities themselves and not be dependent

on others to achieve simple tasks like walking, drinking from a cup, or

turning knobs and buttons.  The movement process generally involves the

primary activation of small motor nerves for fine control, and then

progresses to major activation of motor nerves for movement of larger

muscle groups.

   For example, if one wanted to pick up a cup and all the motor nerves,

small and large were stimulated at once then there would be no function.

 What one would have is a catastrophe as the muscles would not work

together, but separately, and the function of picking up the cup would

be lost.  The brain would not be re-educated as to how to accomplish the

task of picking up a cup, but all the muscles would be spastically

stimulated.

   A true FES unit slowly activates certain muscle nerves and then

slowly activates the larger nerves to achieve a synchronous movement. 

The process repeated over and over, with the patient's active

participation helps the patient relearn and gain self control.  As

previously stated this application is generally indicative of helping a

stroke patient regain function.

   Of course there are other applications for a functional electrical

stimulator such as edema or swelling reduction, retarding disuse atrophy

and also for increasing blood flow.  All of these functions are

appropriate for what is called a muscle stimulator or functional

electric stimulator.  Tens units are not appropriate for the major

functions of muscle stimulation. 
 

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