Progressive Muscle Relaxation

A technique in which a person is trained to voluntarily relax individual muscles. It induces both physiological and psychological relaxation by reducing the response to stress, reducing skeletal muscle contractions, and decreasing the sensation of pain.

Reference:
Field, T. (2009). Progressive muscle relaxation. In Field, T. (Ed.). Complementary and alternative therapies research. Washington: American Psychological Association. pp. 97-101. doi: 10.1037/11859-010.