The aim of the study was to explore the effect of audio-visual biofeedback on patients’ ability to control their own muscle tension, relaxing them. The upper trapezius muscle, which is located on the back of the neck and shoulder part being one of the most tensed human muscles, was studied. The study included 18 volunteers, each had 2–3 relaxation trainings using 4 different biological feedback methods and recording of physiological parameters and patients’ subjective opinion. The obtained measurements were examined to determine the relaxation characteristics of different types of feedback. As a result, it was concluded that the audio-visual biofeedback was recommended to use for muscle relaxation purposes.