Nerve conduction velocity measurement is a kind of neurophysiological examination, which is one of the items in electromyography, mainly used to determine whether the nerve conduction velocity is normal, whether the wave amplitude is abnormal, whether there are other abnormal reflexes, and whether the normal reflexes disappear, and is mostly used to confirm the diagnosis of peripheral nerve disease, to identify peripheral nerve disease, neuromuscular junction disease, and muscle disease. Patients who have multiple peripheral nerve damage, such as multiple peripheral neuropathies, diabetic peripheral neuropathy, uremic peripheral neuropathy, and Green-Barre syndrome, in addition to anterior horn lesions such as motor neuron disease, can have nerve velocimetry done for these diseases to help confirm the diagnosis. If the patient has decreased nerve conduction velocity, decreased wave amplitude, or loss of H-reflex or F-wave, it is indicative of nerve or nerve root damage. If the nerve conduction velocity is normal and the EMG is abnormal, it suggests a possible muscle-derived disease.