Transcutaneous Electrical Nerve Stimulation (
TENS
)
Authors: Johnson Mark I 
Published: April 2013

Transcutaneous electrical nerve stimulation (TENS) is a noninvasive, self‐administered technique to relieve pain. During TENS, pulsed electrical currents are administered across the intact surface of the skin to generate strong nonpainful TENS sensations or mild muscle twitching at the site of pain. TENS inhibits onward transmission of nociceptive (pain‐related) information in the central nervous system and appears to be beneficial for acute and chronic pain. Large meta‐analyses suggest positive outcomes for the relief of musculoskeletal and post‐operative pain, although many systematic reviews are inconclusive. Evidence suggests that some investigators have used small study sample sizes and TENS techniques that are unlikely to be effective based on the findings of studies that have evaluated optimal TENS settings using healthy volunteers. The national institute of health and clinical excellence (UK) recommend TENS for rheumatoid arthritis, osteoarthritis and musculoskeletal pain associated with multiple sclerosis but not for nonspecific low back pain and labour pain. TENS is inexpensive, safe and popular with patients and for this reason practitioners continue to offer patients TENS until better quality evidence emerges.

Key Concepts:

Pain is a major healthcare problem with the prevalence of chronic pain estimated to be greater than 20% in many European countries.

TENS is an inexpensive, noninvasive, self‐administered technique that delivers pulsed electrical currents across the intact surface of the skin to relieve pain.

Conventional TENS is administered using low intensity, high frequency currents to generate a strong nonpainful TENS paraesthesia within the site of pain, and acupuncture‐like TENS is administered using high intensity, low frequency currents to generate a strong nonpainful pulsating TENS sensation often accompanied by muscle twitching.

Conventional TENS is used in the first instance, and acupuncture‐like TENS, which is a form of hyperstimulation, is used for patients who do not respond to conventional TENS.

There is strong neurophysiological evidence that TENS synaptically inhibits onward transmission of nociceptive (pain‐related) impulses in the central nervous system.

Clinical experience suggests that TENS is beneficial for acute and chronic pains that are nociceptive, neuropathic or musculoskeletal in origin.

There are many randomised controlled clinical trials on TENS, but most are methodologically weak with small sample sizes and underdosing of TENS.

The majority of systematic reviews on TENS are inconclusive with the National Institute of Health and Clinical Excellence in the UK recommending that TENS is not cost effective for the management of nonspecific low back pain and established labour pain.

There are some good quality systematic reviews on TENS that suggest that TENS is effective for musculoskeletal pain and post‐operative pain with the National Institute of Health and Clinical Excellence in the UK recommending that TENS is cost effective for the management of rheumatoid arthritis, osteoarthritis and musculoskeletal pain associated with multiple sclerosis.