EMG stands for ElectroMyoGram. NCS stands for Nerve Conduction Study. These are two parts of a test called EMG/NCS or sometimes EMG for short.
What to expect:
The NCS part of the test involves electrical stimulation of the skin on one area (an electrical shock) then over another area of the skin a recording electrode measures the signal further down along the path of the nerve. The computer is able to measure the speed of the nerve and shape of the electrical waveform and tell how healthy a nerve is. The doctor can obtain information about the type and severity of nerve problem by this test.
The EMG which is usually the second half of the test involves the doctor sticking a small pin into different muscles and measuring the electrical activity occurring naturally in your muscles. This not only tells something about the health of the muscles but can also tell something about the health of the nerves that supply those muscles. The pattern of muscles showing abnormalities can help the doctor determine if there is a pinched nerve somewhere, for example in your lower back or neck.
It is helpful if you've taken a shower or bath before the test and are NOT wearing any lotions. Skin oil and lotions interfere with getting a good electrical connection and may make your test take longer than otherwise and can make it harder to get good results. While this test does involve some temporary discomfort it can provide very important information to your doctors. The doctor performing the test will type up a report to send to the referring doctor but usually cannot go over the results with you at the time you have the test. It is best to check back with the doctor that sent you for the test a few days later when she has had a chance to look at the results.