TENS (transcutaneous electrical nerve stimulation) is a process whereby a device produces a mild electric current to stimulate nerves to block pain signals.
Does it work for knees with osteoarthritis?
That’s according to a U.K. study of 224 osteoarthritis patients who were 61 years old on average.
They were split into three groups, all of which received education and physical therapy. One group also got TENS treatments, another got sham TENS therapy (the device looked authentic but produced no electrical current), and the rest got nothing additional, beyond the education and exercise.
If the first group had improved the most, that would be evidence that TENS is effective. If the first and second groups improved more than the third, that would suggest that TENS doesn’t work, but there’s an associated placebo-type effect that does.
Instead we got option three: all three groups were found to have improved the same amount after six weeks, then 24 weeks. (Their levels of pain, stiffness and joint function were assessed; presumably they all benefited from the education and exercise.)
So don’t expect to get pain relief by having someone zap you around your ailing knee.
Of course my new standard disclaimer applies here (in anticipation of the inevitable person who will protest, “But TENS helps me with MY knee pain”).
While this study shows no positive benefit, your mileage may vary. If TENS makes your knees feel better, and the treatment isn’t doing any harm, you might as well keep getting it.