EMG PDF

Electromyography Lab-5 Miss Zaynab Yaseen Ahmed What is Electromyography? Electromyography (EMG) is a diagnostic procedure to assess the health of muscles and the nerve cells that control them (motor neurons). EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-mus...

Electromyography Lab-5 Miss Zaynab Yaseen Ahmed What is Electromyography? Electromyography (EMG) is a diagnostic procedure to assess the health of muscles and the nerve cells that control them (motor neurons). EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-muscle signal transmission. Motor neurons transmit electrical signals that cause muscles to contract. An EMG uses tiny devices called electrodes to translate these signals into graphs, sounds or numerical values that are then interpreted by a specialist. Why it's done? Your doctor may order an EMG if you have signs or symptoms that may indicate a nerve or muscle disorder. Such symptoms may include: 1. Tingling 2. Numbness 3. Muscle weakness 4. Muscle pain or cramping 5. Certain types of limb pain The Electrodes of EMG There are two major types of electrodes used to measure EMG signals—the needle electrode and the surface electrode. Needle electrodes Needle electrodes are approximately 1 mm2 wide which are inserted into the muscle to be tested Surface electrodes are 0.5–2.5-cm wide and due to their positioning are non-invasive. Surface electrodes work on the nerve that activates the muscle. The surface electrodes have electrical activity which are supposed to activate the muscle movement. What Do EMG Results Detect? EMG results are often necessary to help diagnose or rule out a number of conditions such as: 1. Muscle disorders, such as muscular dystrophy. 2. Diseases affecting the connection between the nerve and the muscle. 3. Disorders of nerves outside the spinal cord (peripheral nerves). 4. Disorders that affect the motor neurons in the brain or spinal cord. 5. Disorders that affect the nerve root.