Transcutaneous Electrical Nerve Stimulation
The small, portable, battery-powered TENS devices are worn by the patient and primarily used for pain relief. The TENS unit passes a low voltage current of electricity (impulses of 0-200 pulses per second) to nerve cells through electrodes placed on the patient's skin just below the site where muscle contraction is produced, or on trigger points next to surgical incisions. Pain relief is achieved by counter-irritation of other nerves and by causing the body to release natural pain relieving chemicals. The TENS device can be effective in relieving pain even if worn for an hour.