What is TENS and EMS

Last Updated on October 2, 2023 by Kyle

What are TENS and EMS?

TENS stands for Transcutaneous electrical nerve stimulation.

Transcutaneous electrical nerve stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain. Electrodes or mediums for electricity to travel to the body, placed on the body at the site of pain deliver electricity that travels through the nerve fibers. The electric currents block the pain receptors from being sent from the nerves to the brain.

EMS stands for Electrical muscle stimulation

EMS (Electrical muscle stimulation) is often confused with TENS (Transcutaneous Electrical Nerve Stimulation), a common treatment used in physical therapy offices. It provides an electrical current at a specifically designed frequency to target motor nerves.

These nerves activate the muscle to contract based on the amount of resistance applied through the device. The brain goes through a similar process when actual weights are lifted.

Both types of electric therapies deliver low voltage electric impulses to stimulate nerves or muscles.

TENS stimulates the nerves, with the idea being that the stimulation will disrupt the brain to receive the pain signals from the injured area.

EMS causes the muscles to contract, this mimics muscle movement caused by the nervous system.

TENS (Transcutaneous Electrical Nerve Stimulation)

TENS units are machines that have different adjustable settings to control the amplitude and stimulation by varying voltage.  Electrodes are placed on the certain areas of the body depending on the physical location of pain.

The TENS machine will send current that travels through the electrodes and into the skin stimulating the nerve pathways to produce a tingling and massaging effect to reduce the perception of pain.  When TENS units are used as directed they are a safe, non-invasive, drug-free method of pain management.  A TENS unit is used to provide a better quality of life for those who a suffering from pain.

What does TENS do to Relieve Pain?

There are two basic theories:

  • The Gate Control Theory and is the most advanced explanation. The gate-control theory suggests that a neural mechanism in the spinal cord acts as a kind of gate, shutting down or opening up the flow of signals from the periphery to the brain. Whether the gate is open, closed or partially closed depends on what sort of signal it receives from the brain to change the perception of pain in the user’s body. These frequencies interfere with the transmission of pain messages at the so spinal cord level and help block their transmission to the brain.
  •  The Endorphin Release Theory, which suggests that electrical impulses stimulate the production of endorphins and enkaphalins in the body. These natural morphine-like substances block pain messages from reaching the brain, in a similar fashion to conventional drug therapy, but without the danger of dependence on other side effects.

Many thousands of people use TENS units all over the world for relief of physical pain.  Hundreds of doctors and nurses recommend their patients use TENS units for minor and major pain relief.

Uses of TENS:

  • treatment of chronic and acute pain
  • post operation incision and surgical pain
  • labor and delivery pain
  • migraine and tension headache pain
  • acute sports-related injury pain, for example, ankle pain
  • arthritis pain
  • chronic pain from tendonitis and bursitis
  • wound healing

EMS (Electrical muscle stimulation)

Electric muscle stimulation trains your muscles in a way that traditional workouts alone cannot. Electric muscle stimulation (EMS) — also known as neuromuscular electric stimulation (NMES), muscle stim or e-stim — sends electronic pulses to your motor nerves in order to create muscle contractions.

EMS is also used for re-training muscles that are having trouble contacting. EMS is commonly used for people who have had a stroke or an orthopedic surgery. Many times these patients have trouble trying to move a muscle or joint.

When the electrical impulse is sent into the muscle tissue with e-stim, under the appropriate settings, the muscle can contract without the help of the patient. Doing this while having the subject actively try to contract the muscle can sometimes get the brain to re-learn how to contract the muscle on its own.

EMS provides an electrical current at a specifically designed frequency to target motor nerves. These nerves activate the muscle to contract based on the amount of resistance applied through the device. The brain goes through a similar process when actual weights are lifted.

Uses of EMS

  • Strength training tool for healthy and athletes
  • Speed up Muscle Recovery
  • Rehab tool for those partially or totally immobilized
  • Post-exercise recovery tool
  • Treatment of musculoskeletal injuries such as ankle sprains

Benefits and Shortcomings of TENS and EMS

TENS and EMS have many benefits that support it in being an effective way to manage pain and re-train muscles after injury or disease. TENS and EMS are non-addictive. The machines are often compact and user-friendly.

They are cost-effective and provide many with an alternative to taking pain medications. There are very few risks associated with the use of TENS and EMS. The main shortcoming of TENS and EMS usage is that it will not solve the underlying condition when it comes to pain.

For muscle re-education, the main shortcoming is that even though it can cause a muscle to contract, the function may not return if the neurological damage is severe.


If you are looking at possibly using a TENS or EMS device due to ankle pain or some other type of foot pain, it is important to check with your doctor.  You deserve to feel better and get back to your day-to-day activities.  With the right care and treatment plan, you will be back on health feet in no time.

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