Electromyography or EMG is a test used for measuring and evaluating the electrical activity among the skeletal muscles. EMG test is conducted using a device called the Electromyograph. The record produced from this device is called an Electromyogram which is used by healthcare specialists to evaluate the overall functional strength of the skeletal muscles. Please note that muscle cells function through a series of short, low-strength electrical pulses that are passed through to them by the neurons, i.e. when the muscles get neurologically activated. Thus, via recording the range of electrical signals and analyzing them, any kind of dysfunction among the muscles such as their delayed activation or state of inactiveness can be identified.

Understand EMG Testing
An Electromyograph is adept at recording the minutest of abnormal activity among the muscles. These readings are also indicative of the degree of strength in the muscle contractions and the volume of muscle fibers that are recruited for executing a particular kind of body movement. For instance, when the muscles are fully contracted, a slightly disorderly bunch of waves show on the recordings, indicating that the contraction is reaching maximum levels. EMG is quite useful for diagnosing diseases that arise due to impaired neural activity, i.e. due to problems in the manner in which electrical impulses are relayed among the neurons and from the neurons to the nerves and eventually, to the skeletal muscles. The most common application of EMB testing includes neuromuscular problems such as:

  • Impaired muscle movements due to diseases of the nervous system (neuropathy)
  • Diseases of the Neuromuscular Junction

Understand Nerve Conduction Study—NCS
A Nerve Conduction Study or NCS is used for fully evaluating the electrical conduction performance of the motor and sensory nerves. The motor nerves are the nerves connected to the skeletal muscles. Nerve Conduction Velocity (NCV) is measured during NCS and it helps to fully decipher the electrical conduction ability of the nerves connected to the muscles. This is the reason why Nerve Conduction Studies are used as a part of assessing typical neurological problems wherein the electrical conductivity performance of the nerves is impaired. Symptoms of such typical problems include tingling or burning sensation or sudden numbness apart from unexplained weakness in the arms and legs. NCS is combined with a rigorous Physical Exam and understanding the past medical history of the patient for better diagnosis.

Some neuropathies or diseases of the nervous system that are diagnosed via Nerve Conduction Studies include:

  • Peripheral Neuropathy (involves nerve damage in the peripheral nervous system)
  • Ulnar Neuropathy (ulnar nerve of the arm develops abnormal functioning)

Combining EMG & Nerve Conduction Testing
Often, EMG testing is combined with Nerve Conduction Testing. While EMG is more adept at helping to understand the muscular part of the neuromuscular problems, Nerve Conduction Testing is more useful for fully understanding the neurological part of the problem. Since many neurological disorders cause uncontrolled muscular actions like sudden, jerky movements of the limbs, including that of the hand and feet, apart from uncoordinated movements of the head and neck, combining Nerve Conduction Testing with EMG is regarded as the best clinical testing combination for comprehensively diagnosing neurological diseases.