Research Summary
Adding TENS to Knee Arthritis Exercise Gave No Extra Pain Relief in a Sham-Controlled Trial
Using a TENS unit during exercise therapy did not give people with knee osteoarthritis any extra pain relief compared with a fake (sham) device. That is the finding of a new randomized trial published in Physiotherapy Research International.
What was studied
Exercise is a core treatment for knee osteoarthritis, but pain during movement can make it hard to stick with. Transcutaneous electrical nerve stimulation (TENS) sends mild electrical pulses through pads on the skin and is often used to dull pain. Researchers in Brazil and the United States tested whether high-frequency TENS, applied while patients exercised, would add benefit.
They ran a randomized, sham-controlled trial with 96 people with knee osteoarthritis. Everyone did the same exercise therapy program. Half received active high-frequency TENS during exercise and half received sham stimulation. Participants were intended to be blinded, and the people measuring results were blinded. The main outcome was the pain section of the KOOS knee questionnaire, checked after treatment and again one month later.
Key findings
- Active TENS did not reduce pain more than sham TENS after the program or at the one-month follow-up.
- The differences were far smaller than the 10-point change the researchers set as clinically meaningful.
- No differences were found in any other outcome, including other KOOS sections, pain intensity, confidence in managing pain, disability, thigh muscle strength and physical function.
- No side effects were reported.
What it means for people with knee pain
The exercise program itself remains the key part of treatment. This trial suggests that adding a TENS unit during exercise sessions is unlikely to make the program work better, so it may not be worth extra cost or time for that purpose.
Limitations
The authors note that blinding was not formally checked, follow-up lasted only one month, and there was no exercise-only group for comparison. The study tested TENS during exercise, not TENS used on its own for pain at other times.
Frequently asked questions
- What is TENS?
- TENS (transcutaneous electrical nerve stimulation) is a small device that sends mild electrical pulses through pads placed on the skin. It is commonly used to try to reduce pain.
- Does TENS make knee arthritis exercise more effective?
- In this trial of 96 people, adding high-frequency TENS during an exercise program did not improve pain, function or strength more than a sham device.
- Was TENS safe in this study?
- Yes. The researchers reported no adverse effects in either group.
Sudden severe pain, swelling, or can't bear weight? Seek medical care promptly. In an emergency call 911.