elektromyografiaa

Elektromyografiaa, or electromyography (EMG), is a technique for evaluating and recording the electrical activity produced by skeletal muscles. It can be performed with needle electrodes inserted into a muscle or with surface electrodes placed on the skin. Needle EMG provides detailed information about individual motor units, while surface EMG is noninvasive and suited to measuring activity during movement. High-density EMG uses arrays of electrodes for comprehensive mapping.

EMG analyzes motor unit action potentials, firing rates, and recruitment patterns to assess neuromuscular function. At rest, spontaneous activity such as fibrillations may indicate pathology. During contraction, the pattern of electrical signals reflects how nerves activate muscle fibers. Data are interpreted by trained clinicians and researchers and may be complemented by nerve conduction studies (NCS) to distinguish nerve from muscle disorders.

Clinical uses include evaluation of weakness, numbness, and suspected neuropathies or myopathies. EMG assists in diagnosing conditions such as radiculopathy, neuropathy, myopathy, and motor neuron disease, and is used to monitor nerve injuries or disease progression. In research, EMG supports studies of motor control, fatigue, rehabilitation, and human–machine interfaces.

Safety and limitations: EMG is generally safe with minimal risk; needle insertion can be uncomfortable, and there is a small risk of bleeding or infection. Accuracy depends on proper electrode placement, patient cooperation, and avoiding cross-talk between muscles; interpretation requires expertise and can be affected by skin impedance and body habitus.