Nerve conduction study and electromyography (NCS – EMG)
EMG and NCS are tests that measure the electrical activity of the muscles and nerves of the body, usually to an arm or a leg. The tests can help identify nerve injury or muscle disease such as carpal tunnel syndrome, a pinched spinal nerve, peripheral neuropathy, myositis, or ALS.
EMGs can detect abnormal muscle electrical activity in many diseases and conditions. It is particularly useful in conditions such as muscle inflammation or myositis, pinched peripheral nerves like carpal tunnel syndrome, disc herniation with pinched nerves, ALS, and many more conditions.But if your muscle is damaged or has lost input from nerves, it may have abnormal electrical activity during rest. … An abnormal EMG result may be a sign of a muscle or nerve disorder, such as: Polymyositis. This is an inflammatory muscle disease that causes decreased muscle power.