[TENS machines (Transcutaneous Electrical Nerve Stimulation) are small, battery-operated pulse generators used externally, with two or more small electrodes, to alleviate localised pain. The electrical pulses travel along the nerve pathways and block pain messages, so your perception of pain is dulled. The pads are attached to a handset which allows you to control the frequency of the electrical pulses.

(Talk Back, National Back Pain Association, Autumn '94, p11)

The October 1990 issue of Talk Back reports on the progress of a research project into the effectiveness of TNS (transcutaneous nerve stimulation).