Which technique is used to record the electrical activity in muscles at rest and during contraction?

The technique used to record the electrical activity in muscles at rest and during contraction is electromyography (EMG). EMG works by placing electrodes—either surface or inserted into the muscle—on the skin or within the muscle to detect the electrical signals generated by muscle fibers. This allows for the assessment of muscle function, detecting abnormalities in nerve-to-muscle signaling, or evaluating the effectiveness of rehabilitation strategies.

In contrast, electrocardiography (ECG) is specifically designed to measure the electrical activity of the heart, not muscles. Ultrasound imaging provides visual images of the internal structures, including muscles, but does not measure electrical activity. Magnetoencephalography (MEG) is a technique used primarily to measure the magnetic fields generated by neuronal activity in the brain, thus, it is not relevant for muscle activity recordings. Therefore, electromyography is the definitive choice for recording the electrical activity of muscles.