EMG basics part 3: Purpose of Needle EMG

This content includes a lot of grammatical and vocabulary errors.Please cut me some slack from Japan.

In this article, we will discuss the purpose of performing EMG testing in the first place.

Are you being hit now?

As the title says, is the muscle or nerve in the middle of hurting right now, i.e., is it an acute disease? The main purpose of the needle EMG test is to differentiate between a muscle or nerve that is in the process of being injured and one that is in an acute stage.

If the disease is “being treated right now,” the results are very important because treatment may cure the disease or prevent it from progressing. On the other hand, if the disease is “already beaten up,” it will be difficult to recover even if the disease is treated.

Objective examination

This is another important purpose of the needle myogram.

We use a manual muscle test (MMT), which is a six-point scale from 0 to 5, with 0 being no strength at all and 5 being normal. On a scale of 0-5, where 0 means no force at all and 5 means normal.

The test is performed to see if the limb can move against the force or gravity we give it. For example, the biceps brachii is the muscle that bends the elbow, so we try to get out of the way, i.e., extend the elbow, to see if it can withstand the force.

But this is a very subjective test. If a macho person tests it and a frail woman tests it, there will be an error in the results no matter how you look at it. (Inter-rater error).

Also, if the muscles move only a little, it may be misdiagnosed as not being forceful (false negative).

On the other hand, needle electromyography is a very objective test because it can observe even small muscle activity and express muscle activity numerically.

Future Recovery Guideline

In addition, as in the previous MMT, electromyography allows prior confirmation of muscle activity before recovery is recognized by the naked eye or physical examination. This is actually very important and can predict the possibility of subsequent recovery.

On the other hand, if there is no muscle activity at all, recovery will be difficult. However, if we know that recovery is difficult, we can consider alternative measures, etc., and link them to subsequent treatment. In this respect, it is still a very important test.

That’s all. Thank you again.