Injury Diagnosis with EMG & Nerve Conduction Studies

This outpatient diagnostic test is used to evaluate the health of muscles and the nerves, called motor neurons, which control the muscles. EMG is a valuable diagnostic device for determining the cause of muscle weakness and for identifying neurologic disorders. 

At Seattle Spine & Sports Medicine, our physician providers have core training and expertise with this specialized technique.  We work hard to put patients at ease, and to minimize patient discomfort with this valuable diagnostic tool.

Electromyography & Nerve Conduction Studies

These are diagnostic studies that allow us to “write down of the electrical activity of muscle” and “measures how fast nerve impulses travel within your body”.  We perform this procedure to help diagnose nerve and muscle injuries.

WHAT IS NCS?

  • Nerve Conduction Studies (NCS) measure how fast nerve impulses travel within your body. A blockage may indicate nerve injury. This diagram shows the NCS procedure for detecting carpal tunnel syndrome.
  • The doctor presses a surface electrical stimulator on your skin overlying a specific nerve and then stimulates the nerve with a brief electrical pulse.
  • Surface electrodes are placed over a muscle or patch of skin (supplied by the nerve) to detect the response.

WHAT IS AN EMG?

  • Electromyography (EMG) translates to "the writing down of the electrical activity of muscle." It is similar to the electrocardiography (EKG) for the heart.
  • To sample muscle electrical activity, a small needle electrode—much smaller than a standard needle for drawing blood—is inserted into a muscle. You may be asked to contract the muscle. This procedure may be repeated for a few or for a number of your muscles.
  • The electrode is connected to a computer for analysis.

WHAT SHOULD yOU ExPECT FROM THE PROCEDURES?

  • Prior to the test you can eat and take your usual medications.
  • With NCS, you may feel sensations similar to static electricity as well as twitching of muscles. Most patients have good tolerance of these sensations.
  • For the EMG, some patients have no discomfort, while others may have some level of pain when the electrode is placed within the muscle. If you're anxious about this procedure, call our office and we may be able to pre-medicate and help sedate you. You must be accompanied by a designated companion and driver.
  • When the examination is over, there is usually no further discomfort. Afterwards, we generate a typed report.  Your doctor uses this report with other information to help decide a treatment plan.

For more information, see our available brochure:

Start on the road to feeling better...

Website Design