Nerve Conduction Studies

Nerve conduction study (NCS) is another part of electrodiagnostic study which is performed along with Electromyography.

Nerve Conduction Studies measure the speed of the nerves in sending electrical impulses. This test determines the specific site of injury such as pinch or damage nerves.

The nerve conduction technician puts electrode patches to skin directly on the belly of the muscles innervated by the nerves and apply mild electric shocks in order to measure the speed of nerve conduction and nerve response. This part of the exam may take half an hour to 45 minutes, depending on how many nerves and muscles are being tested.
This test is often used to help find nerve problems such as:

  • diabetic neuropathy
  • carpal tunnel syndrome
  • herniated disk disease
  • sciatic nerve problems
  • pinched nerves
  • peripheral nerve injury

Electrodiagnostic testing is also helpful in determining the extent of injury to a nerve after an accident or any effects of alcohol or drug abuse or diseases such as diabetes mellitus, high blood pressure or hypothyroid disease.
To get ready for this exam, make sure that you inform your doctor about all the medications you are taking including the over the counter ones which could affect the result of this study. Patients are also informed not to use lotions or oils on the extremities being tested.
The result of this test is usually available in 24 to 48 hours.

Information about Electrodiagnostic Study

Electrodiagnosticstudy reveals the condition of your nerves and muscles and can also determine the presence, nature and degree of any damage. This study also verifies any unexplained nagging pain, numbness, tingling sensation, weakness or muscle cramping. California Sports & Rehab specializes in performing electrodiagnostic study which consists of two parts, first part is Nerve conduction study and the second part is Electromyography.

Nerve Conduction Studies (NCS) 

This study measures how fast an electrical impulse can travel through your nerve. Electrodes are placed on the skin over the affected nerve. Multiple small electrical pulses are given to the nerve and the resulting electrical activity is recorded. Depending on the symptoms, several nerves may be tested. These impulses cause electrical sensations that may cause a quick, tingling feeling. This test may take half an hour to 45 minutes, depending on how many nerves and muscles are being tested.


This study is used to evaluate and determine the cause of pain, muscle weakness, numbness and tingling sensation. This portion of the test usually takes 10 to 15 minutes and involves a small, thin sterile acupuncture electrode that is inserted into the muscles and the electrical activity is measured and recorded when the muscle is at rest and during contraction. During the EMG the electrical activity is displayed visually and audibly on a computer’s monitor. Most patients feel no discomfort with this procedure, however, an individual may experience a small amount of discomfort during this part of this test such as tenderness or soreness for a few days and possibly small bruising. Inform your doctor if these symptoms persist.

Why is this test performed?

Tingling sensation, numbness, muscle weakness, pain or cramping and certain types of limb pain are signs or symptoms that may indicate a nerve or muscle disorder.

Common conditions that require Electrodiagnostic testing:

Carpal Tunnel Syndrome: A condition in which the median nerve traveling through the wrist is compressed or squeezed and often cause tingling sensation or numbness at the thumb, index and long fingers.

Cubital Tunnel Syndrome: A condition in which the ulnar nerve is compressed at the elbow causing numbness and tingling sensation at the 4th and 5th fingers.

Radial Neuropathy: Acute trauma to the radial nerve that extends from the thumb up the length of the arm to the shoulder.

Diabetic Neuropathy: Nerve damage that occurs with diabetes.

Herniated Disk Disease: An injury to the rubbery cushion (disc) between the vertebrae of the spine.

Sciatic Nerve Problems: Pain radiating from the lower spine running down one or both of the backsides of the leg.

Peripheral Nerve Injury: Peripheral nerve damage that gives a weakness, numbness and pain sensations.

How to prepare for the Test:

  • Bring a valid photo I.D.
  • Once in the office you will be provided forms to fill out such as consent for your permission to do the test, a questionnaire regarding pain, how the injury occurred and basic information.
  • Inform the technician or doctor of any medications you may be taking whether it is prescription, over-the-counter or herbal.
  • Dress comfortably and allow easy access to areas needed to be tested.
  • You may be asked to remove articles of clothing. Disposable shorts and gowns are provided.
  • Jewelries, hearing aids, cell phones and other metal like objects may be asked to be removed to prevent interference with the conduction.
  • Take a shower to remove excess oil from your skin. Do not use lotions or oils before the exam.


The result will be available in 24-48 hours and a report will be sent to your primary or referring physician.

If you want to fill out the forms in advance prior to your set appointment, please click the link below. EMG/NCS Consent Forms