EMG biofeedback operates on the principle of operant conditioning, where individuals learn to modify their behavior based on the feedback they receive. The process begins with the placement of surface electrodes on the skin over specific muscles that the therapist aims to monitor. When the targeted muscle contracts, it produces electrical signals, which are measured in microvolts. These weak signals are then amplified by the EMG machine to make them readable. The amplified data is converted into visual displays, such as graphs or blinking lights, or into auditory cues like beeps or changes in pitch. Patients observe or listen to this feedback and attempt to alter or maintain the muscle activity based on their therapeutic goals. For instance, a patient with weak quadriceps may be shown a graph representing muscle activity and encouraged to raise the bar higher by contracting the muscle more forcefully. Through repeated practice and feedback, patients gradually learn to activate and control their muscles more effectively.