An electromyogram (EMG) measures the electrical impulses of muscles at rest and during contraction.

An EMG is done to:

• diagnose diseases that damage muscle tissue, nerves, or the junctions between the two (i.e. herniated discs)
• evaluate the cause of weakness, paralysis, or involuntary muscle twitching

Nerve conduction studies determine how well individual nerves can transmit these electrical signals.

A nerve conduction study is done to:

• detect and evaluate damage to the nerves that lead away from the brain and spinal cord
• help diagnose nerve disorders (i.e. carpal tunnel syndrome)
• identify the location of abnormal sensations, such as numbness, tingling, or pain