Electrical muscle stimulation involves sending electrical impulses through the skin. This stimulation may provide benefits, such as helping repair tissue and strengthening the muscles.

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The electrical impulses mimic what occurs when someone contracts and releases a muscle naturally. Physical therapists and doctors use this technique to treat people with various diseases and injuries.

The article below takes an in-depth look at what electrical muscle stimulation involves, how it works, its uses, its risks, and possible alternatives.

Electrical muscle stimulation, called E-stim, uses special devices to send electrical impulses through the skin to target nerves or muscles.

There are a few types of electrical muscle stimulation. The most common forms include transcutaneous electric nerve stimulation (TENS) and electrical muscle stimulation (EMS).

TENS and EMS involve applying electrodes to the skin near an affected muscle to send an electrical current to the area. This current causes rhythmic muscle contractions.

An early form of electrical muscle stimulation dates back to the first century. A Roman doctor found that patients with gout experienced a decrease in pain after exposure to an electrical shock.

In the early 18th century, doctors used devices to deliver electrical shocks to treat various conditions. Electrical muscle stimulation units continued to evolve through the years into modern devices and technology.

Doctors use electrical muscle stimulation to help treat pain and heal injured, weak, or diseased muscles. The electrical currents may help improve blood flow and stimulate the muscle fibers or nerves.

Physicians may recommend TENS or EMS depending on the injury or condition.

EMS may help the muscles respond to natural signals to contract. This response helps strengthen or retrain a muscle after surgery or an injury. Healthcare professionals may recommend TENS therapy to help increase blood flow to the area and reduce pain. This technique help muscle firing patterns.

There are also other uses for electrical muscle stimulation, including as an aid for weight loss and physical therapy.

Currently, the Food and Drug Administration (FDA) has only cleared electrical muscle stimulators for use in treating medical conditions. Doctors may use the devices to help relax:

  • muscle spasms
  • retrain muscles
  • prevent muscle loss

Pain is a major problem for millions of people throughout the world.

A 2019 study indicates that chronic pain affects about 45% of adults worldwide, with up to 15% of those individuals reporting severe disabling pain.

Some forms of electrical muscle stimulation may help treat pain relating to injuries and diseases. For example, according to the Arthritis Foundation, using a TENS unit may help reduce pain due to osteoarthritis.

How it works

Healthcare providers typically recommend using TENS units for pain. These devices deliver electrical currents to the nerves, which may reduce pain signals, providing pain relief. The currents may also trigger the release of endorphins in the brain that help reduce pain naturally.

A 2021 systematic review and meta-analysis of 381 randomized clinical trials involving 24,532 supported TENS treatment for pain. The review found that pain intensity was lower during and after treatment with TENS than with a placebo.

Benefits

Some form of electoral muscle stimulation, such as a TENS unit, may reduce chronic pain symptoms.

Electrical muscle stimulation may help decrease the need for pain medication and its side effects. Reducing pain helps improve the quality of life for people with long-term symptoms.

Read more about what pain is and how to treat it.

Physical therapists sometimes use electrical muscle stimulation as a treatment tool. This technique may help treat conditions that cause weakened or injured muscles.

How it works

Electrical muscle stimulation can cause repeated muscle contractions, which strengthen atrophied or weakened muscles.

As part of a physical therapy program, research from 2019 has shown that Russian stimulation, a technique involving high-frequency electrical muscle stimulation, is beneficial in improving muscle force-generating ability.

Researchers used this type of stimulation after knee ligament surgery to aid the activation of muscle fibers. This helped engage the quadriceps to improve knee extension.

However, due to the small sample size and uncontrolled nature of this study, there are some limitations in determining how conclusive the findings are.

Benefits

As part of a physical therapy program, electrical muscle stimulation may help people deal with issues affecting the muscles, such as:

It may help in treating various conditions that affect muscle strength, such as:

There appear to be very few risks relating to electrical muscle stimulation. The most common include tissue burns and skin irritation.

However, additional complications can occur if the placement of the electrodes is too close to a transdermal drug patch.

Electrical muscle stimulation may not be appropriate for everyone. Doctors may not recommend it to people who:

  • are pregnant
  • have implanted pacemakers
  • have epilepsy

Health experts are unsure of the benefits of electrical muscle stimulation as a medical treatment, as studies have yielded mixed results. For example, a 2022 study indicates that people using it reported lower pain levels after TENS than the placebo group.

However, other research does not support the same results. Another study found that TENS did not improve symptoms of lower back pain, but it may provide short-term improvement of disability.

Further research must determine its effectiveness and widespread use as a treatment option.

Various types of devices are available to buy without a prescription. Different units feature varied:

  • electrode sizes
  • program modes
  • strength levels

The best device to purchase may depend on the condition a person wants to treat and their budget.

Find out more about the best TENS units.

While electrical muscle stimulation is one option for treating pain and conditions that affect the muscles, doctors and therapists also have many other alternatives. Other forms of therapy and treatment may include:

Electrical muscle stimulation involves sending electrical impulses to the muscles. This process may promote blood flow and strengthen the muscles. It may also affect pain signals, reducing discomfort.

Electrical muscle stimulation is available to treat various muscle issues and pain. However, additional studies must confirm the effectiveness as a general treatment for a wider range of conditions.