Electrical Nerve Stimulation (TENS)
Electrical Nerve Stimulation (TENS) is a therapy that uses low-voltage electrical current for pain relief.
When the current is delivered, some people experience less pain. This may be because the electricity from the electrodes stimulates the nerves in an affected area and sends signals to the brain that block or “scramble” normal pain signals. Another theory is that the electrical stimulation of the nerves may help the body to produce natural painkillers called endorphins, which may block the perception of pain.
The unit is usually connected to the skin using two or more electrodes. A typical battery-operated TENS unit is able to modulate pulse width, frequency and intensity. Generally TENS is applied at high frequency (>50 Hz) with an intensity below motor contraction (sensory intensity) or low frequency (
A few studies have shown objective evidence that TENS may modulate or suppress pain signals in the brain. One used evoked cortical potentials to show that electric stimulation of peripheral A-beta sensory fibers reliably suppressed A-delta fiber nociceptiveprocessing.] Two other studies used functional magnetic resonance imaging(fMRI): one showed that high-frequency TENS produced a decrease in pain-related cortical activations in patients with carpal tunnel syndrome, while the other showed that low-frequency TENS decreased shoulder impingement pain and modulated pain-induced activation in the brain.
Here are some points about TENS as a form of pain relief:
- A drug-free alternative way to treat the symptoms of pain
- Can potentially replace other forms of treatment, such as pain medication – for people who are unable to – or don’t want to take drugs because of the side effects
- Its effectiveness varies depending upon the pain and individual being treated
- Is often administered alongside and combined with other forms of treatment
- Not a cure for conditions, whereas other treatments (like physical therapy, surgery or medication) may be able to address the root cause
- Not clear conclusive scientific research to prove whether it’s an effective method for relieving pain
- According to healthcare professionals, it seems to help some people
- Evidence to support TENS as a treatment for patients experiencing chronic pain
- Significant body of evidence supporting TENS as an effective intervention in acute pain conditions