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== Uses == == Uses ==
FUCK!!!
EMG can help to distinguish primary muscle conditions from muscle weakness caused by neurologic disorders. EMG can help to distinguish primary muscle conditions from muscle weakness caused by neurologic disorders.
It can be used to differentiate between true weakness and reduced use due to pain or lack of motivation. It is used to find causes of weakness, ], involuntary twitching, and abnormal levels of muscle ]s. It can help diagnose neuromuscular disorders such as ], ], nerve damage and muscle damage. See ]. It can be used to differentiate between true weakness and reduced use due to pain or lack of motivation. It is used to find causes of weakness, ], involuntary twitching, and abnormal levels of muscle ]s. It can help diagnose neuromuscular disorders such as ], ], nerve damage and muscle damage. See ].


Electromyography is also used in ] studies and training. Electromyography training is a kind of biofeedback in which patients learn to control muscle tension in the face, neck, and shoulders. For example, such training is sometimes given to ] patients. Electromyography is also used in ] studies and training. Electromyography training is a kind of biofeedback in which patients learn to control muscle tension in the face, neck, and shoulders. For example, such training is sometimes given to ] patients.




== Normal results == == Normal results ==

Revision as of 16:14, 2 July 2006

Electromyography (EMG) is a medical technique for measuring muscle response to nervous stimulation. EMG is performed using an instrument called an electromyograph, to produce a record called an electromyogram. An electromyograph detects the electrical potential generated by muscle cells when these cells contract.

Electrical Characteristics

Electrical source is the muscle membrane potential, about -70mV. Due to the applied method the resulting measured potentials might range between 50μV and 100mV.

Typical repetition rate of muscle unit firing is about 7-20Hz, depending of the size of the muscle (eye muscles versus seat (gluteal) muscles), previous axonal damage and other facts.

Uses

FUCK!!! EMG can help to distinguish primary muscle conditions from muscle weakness caused by neurologic disorders. It can be used to differentiate between true weakness and reduced use due to pain or lack of motivation. It is used to find causes of weakness, paralysis, involuntary twitching, and abnormal levels of muscle enzymes. It can help diagnose neuromuscular disorders such as Motor Neurone Disease, neuropathy, nerve damage and muscle damage. See #Abnormal results.

Electromyography is also used in biofeedback studies and training. Electromyography training is a kind of biofeedback in which patients learn to control muscle tension in the face, neck, and shoulders. For example, such training is sometimes given to migraine patients.

Normal results

Muscle tissue at rest is normally electrically inactive. After the activity caused by the trauma of needle insertion subsides, the electromyograph should detect no action potential. When the muscle is voluntarily contracted, action potentials begin to appear. As contraction is increased, more and more muscle fibers produce action potentials. When the muscle is fully contracted, there should appear a disorderly group of action potentials of varying rates and amplitudes (a complete recruitment and interference pattern).

Abnormal results

Abnormal results may be caused by the following medical conditions:

References

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