Transcutaneous electrical nerve stimulation (TENS) is a device used for therapeutic purposes which stimulates the nerves and is often used in the treatment of muscular, joint and nerve pains. A TENS machine uses electrical pulses that are transmitted to the body through pads which are placed upon the area where the underlying cause of pains are originating from. Although research performed looking in to the effectiveness of TENS machines have been completed the results are still inconclusive. However it is a treatment modality which is widely used in the treatment of pain and individuals have seen great improvements from using the devices. If used properly the TENS machine is a safe treatment option with no or few associated side effects.

How the TENS machines work

Pain is a protective mechanism which can cause different sensations and intensities to the individual. It has been described as an unpleasant sensation with an associated emotional response attached to the actual or the potential for tissue damage. Contrary to popular belief, pain is actually registered within the brain and sends signals to the area that is damaged and act as a defensive mechanism to ensure no further harm is done to the area.

It is thought the TENS machines works in two ways. The normal method of use which is at a frequency of 90-130Hz. It is thought that this frequency stimulates, interferes and actually blocks the nerves that transmit the pain signals to the brain. This is what’s known as the pain gate theory which consists of the central nervous system, nerves and spinal cord. Pain is felt when this gate is open and the stimuli is being transmitted by the nerves to the brain. TENS machines work by stimulating the non-pain specific nerve signals which are transmitted faster than what the pain transmitting nerves can conduct, this then closes the pain gate which leads onto pain relief.

Another way that the machines work is by using a low pulse rate of 2-5Hz. This is thought that it stimulates the body’s own pain relieving chemicals called endorphins. These endorphins act in the same way morphine would to block the pain signals.

Who can use the TENS machine?

A TENS machine can be personally used by the individual but it is advisable to see a health care professional first and undergo an assessment as not everybody is suitable to use the device. The machines can be used with the sole purpose of treating pain or they can be used in conjunction with other treatment modalities. It is often used to treat the following:-

  • Neck pain
  • Knee pain
  • Period pain
  • Back pain
  • Arthritis
  • Sports injuries
  • Chronic pain

Those that should not use a TENS machine are:-

  • Undiagnosed cause of the pain
  • If you are epileptic
  • If you have certain types of heart disease
  • Pacemakers
  • Pregnancy


A TENS machine is an accepted form of treatment used or given to their patients by physiotherapists. Pain is felt when the pain gait is open, TENS works by stimulating the non-pain specific nerves that travel to the brain faster than the nerves that transmit pain. This is called closing the gate. It can have great impact on some individuals and relieve their pain which can then lead onto to a better quality of life.

Booking an appointment

If you would like to book a physiotherapy appointment or would like further information regarding what we do please email us on or call us on 01245 830280.