'In principle, TENS applies an electrical force that stimulates pain-suppressing A-beta afferent nerve fibres which compete against pain-carrying afferent nerve fibres. The same stimulation would occur if one lightly tapped the painful part of the body repeatedly with a pen, spoon, or other blunt object. Ice, massage, heat, manipulation and other long-standing therapy techniques have relieved pain this way for centuries.'
Dr. Kirsch & Dr. Lerner; The Textbook of the American Acadamy of Pain Management Chapter 23, Electromedicine.
