Electromyography (EMG) in Orthopedics: Evaluating Nerve and Muscle Function


Electromyography (EMG) is a valuable diagnostic tool used in orthopedics to assess the health and function of muscles and the motor neurons that control them. This outpatient test helps identify the cause of muscle weakness and diagnose various neurologic disorders. This article provides an overview of EMG, its applications in orthopedics, the testing procedure, patient preparation, and the expected timeline for receiving results.

Understanding EMG:

EMG consists of two parts: the nerve conduction study and electromyography. Conducted by Physical Medicine & Rehabilitation physicians or neurologists, this test evaluates nerve and muscle function, providing insights into conditions affecting the musculoskeletal system.

Conditions Diagnosed with EMG:

EMG is useful in diagnosing several orthopedic conditions, including:
Carpal Tunnel Syndrome: A compression of the median nerve in the wrist leading to hand pain and weakness.
Ulnar Nerve Compression: Compression of the ulnar nerve, often causing symptoms in the elbow, forearm, and hand.
Radiculopathy (pinched nerve): Nerve compression in the spinal region resulting in radiating pain, numbness, or weakness.
Neuropathy: Damage to peripheral nerves causing symptoms like numbness, tingling, and muscle weakness.
Nerve injury: Assessment of nerve damage caused by trauma or other factors. Unexplained numbness, tingling, or weakness: Evaluating symptoms without an obvious cause.


EMG consists of two main components:
Nerve Conduction Study: The patient is connected to electrodes placed on various hand muscles. Electrical stimulation is applied to the nerves, causing muscle contractions. This part of the test helps evaluate the speed and integrity of nerve signals.
Electromyography: A fine wire or pin with a recording device is inserted into specific muscles. This allows the detection of nerve damage and assessment of muscle function. The sensation experienced during this part of the test is often described as similar to acupuncture.

Patient Preparation:

To ensure accurate results, patients should:
Avoid using lotions, creams, or oils on the day of the test, as they can interfere with the test results.
Continue taking prescribed medications, including blood thinners, unless instructed otherwise.
Inform the physician if they have an implanted device such as a pacemaker or stimulator, as this may impact certain aspects of the test.

Test Duration and Result Expectations:

EMG tests are typically well-tolerated and cause minimal discomfort. The procedure usually takes 20-30 minutes to complete. Since EMGs are performed by a physician, they can often analyze the results in real-time. In complex cases, the physician may take additional time to review the findings before sharing them with the referring physician.
The physician who conducted the EMG will communicate the results to the referring physician. Subsequently, the patient will schedule an appointment with the referring physician to discuss the results in detail and develop an appropriate treatment plan.


EMG is a valuable diagnostic tool used in orthopedics to assess nerve and muscle function. By conducting a nerve conduction study and electromyography, physicians can identify the cause of muscle weakness and diagnose various neurologic conditions. EMG tests are generally well-tolerated, brief, and provide prompt results. By utilizing EMG, orthopedic specialists can gain critical insights into patients’ conditions, facilitating the development of effective treatment plans and enhancing overall patient care.