What Does The Research On TENS Units Show?

TENS units are small battery operated devices that deliver an electrical current to the skin by way of surface electrodes. These units are inexpensive (usually less than $100), safe, and are non-invasive.

In 1965 Melzack and Wall published their pain gate theory which proposed that a gate existed in part of the spinal cord which could regulate the traffic of painful sensations. When administering the current with TENS, the objective is to activate the non-painful fibres which can then inhibit transmission of painful information. TENS modulates the method by which patients process the pain sensations from the anatomical area, and potentially help release endorphins that act as natural painkillers.

With regards to adverse effects of TENS units, most studies show no adverse effects at all. Some, however, showed an incidence of nausea, bradycardia, and dizziness. Some patients experienced pain, burning, and tingling at the electrode site. It does not interact with medications, and it does not make people drowsy. It is easy to put on, and can be worn during most physical activities. One contraindication is pregnancy, and another one is if the person has a pacemaker.

In a comprehensive review of published studies on TENS units, it has been shown that the quality of research over the past 2 decades has overall been poorly done. So it is difficult to make scientific conclusions. There have been well over 100 studies performed looking at the efficacy of TENS units, however, very few actually contained sufficient numbers to achieve any sort of statistical significance.

Even though most of the studies were of poor quality that were looked at, some showed excellent results for low back pain, arthritis pain, postsurgical pain, neurogenic pain, and sympathetically medicated pain.

There was one study looking at TENS usage after surgery in the 2003 Journal of Pain. It showed excellent results utilizing TENS after abdominal surgery. TENS allowed increased activity and decreased pain during patient's walking and breathing exercises. A lot of studies have shown no statistical difference between TENS unit effects and placebo.

The Osteoarthritis Research Society International recommends TENS units for short term pain relief of hip and knee osteoarthritis. They looked at seven research trials prior to making this recommendation.

When practitioners are asked how well TENS works for patients with musculoskeletal pain, the anecdotal reports are very promising. With it being so low-risk, it is a very prominent treatment option that gets utilized frequently for acute and chronic painful issues.