During e-stim treatment, a therapist secures electrode pads to your skin. He or she then turns a dial or presses a button on an electrical muscle stimulation device, a console that’s either plugged into the wall or battery-operated. This machine generates electric impulses that stimulate your skeletal muscles to contract. An e-stim device has various settings, meaning the contractions may be barely noticeable or they may feel, and look, like involuntary muscle twitches.

The primary purpose of e-stim therapy is to simulate what happens in the body when you voluntarily contract and release a muscle many times in a row. This process strengthens and repairs tissue, particularly muscles which have become shortened, weakened, or atrophied due to injury or disease. For example:

If you’ve torn an Achilles tendon, the muscles in your calf and foot may become atrophied from wearing a boot to immobilize the ankle, or from changing your gait to favor the injured ankle.

If you have a shoulder injury (e.g., a rotator cuff tear or impingement), resting, immobilizing, or favoring the shoulder may cause the muscles in and around that shoulder to weaken.

If you have neuromuscular dysfunction or a neuromuscular disorder (such as muscular dystrophy), muscles throughout the body may weaken progressively; e-stim can help to slow this progression and improve motor control.

E-stim can also be used by athletes as a muscle conditioning or recovery tool. Some studies have indicated that e-stim can be targeted to create contractions in different types of muscle fibers, allowing athletes (with the guidance and help of professional sports therapists) to train injured or weakened muscles for particular functions and responses. For example, a long-distance runner might use e-stim therapy as a complementary technique to train muscle fibers to resist fatigue.

HOW EXACTLY DOES E-STIM WORK?

EMS therapy mimics the action potential that comes from the central nervous system. The action potential is what we call it when a neuron (cell in the nervous system) transmits information (electrical impulses) along an axon (the thread-like conduit leading away from the neuron body, toward other cells). When these impulses pass a threshold, the action potential is fired and something happens. In this case, that something is a muscle contraction.

EMS therapy creates steady electric impulses that stimulate muscle contractions–many of them over a sustained therapy session. This repetitive contracting and relaxing of the muscle have the effect of:

Increasing circulation (blood flow) to the affected tissue area, aids in repair.

improving strength by flexing and working weakened muscles.

slowing the process of muscle atrophy by strengthening weakened or unused muscles.

adapting (training or “educating”) muscle fibers to certain patterns of response (e.g., contracts the fibers that are responsible for force, which results in building strength).

Another form of e-stim therapy called TENS (transcutaneous electrical nerve stimulation) works on nerves rather than muscles. It’s used primarily for managing or blocking pain signals to the brain and has been in regular use by doctors and physical therapists since the 1960s.

TENS therapy can issue electrical stimulation at different wavelengths for different purposes (relaxation, circulation, blocking pain) and can sometimes be performed at home after the patient has been taught the proper and safe use of the equipment.

 USES AND BENEFITS OF E-STIM THERAPY

When used for recovery, rehabilitation, muscle training, or pain relief, EMS and TENS devices are normally prescription-only and administered by professionals: for example, sports medicine physicians, physical therapists, or orthopedists. There are, however, some devices available for over-the-counter purchase and home use.

Some of the common uses of prescription EMS therapy include:

Relieving back spasms. Electric muscle stimulation can relax back muscles, easing tightness and soreness in the lower back area. Sciatica symptoms, for example, can be caused by back muscles in spasm. Stopping the spasm may relieve the pressure on the sciatic nerve. EMS can also help with muscle tightness and soreness from other spinal issues, including postural problems and scoliosis

Working weakened or atrophied muscles. Broken bones, soft tissue injuries, spinal cord injuries, neuromuscular disorders, stroke, and certain forms of illness can inhibit movement and exercise, causing muscles to become weak from disuse. E-stim can be used to keep these muscles active and prevent atrophy.

Retraining muscles after surgery or illness. Occasionally, following orthopedic surgery or illness (such as a stroke), a patient may have difficulty contracting muscles at will. In such cases, e-stim can be used for “muscle re-education.” The electrical impulses contract the muscle involuntarily. If the patient concentrates on voluntarily contracting this muscle during the therapy, the brain may re-learn how to do so without help.

Aiding athletic recovery. E-stim active recovery program settings use specific low-level frequencies to increase blood flow, remove lactic acid, release endorphins, and promote muscle relaxation. Athletes working out at high-intensity levels–who may be prone to intense cramping or spasms–may find this program beneficial. Endurance athletes, for example, may wish to work regular e-stim sessions into their routines so they can keep their muscles loose and continue training without injury.

 

TENS therapy, on the other hand, is normally used to manage pain (acute or chronic), rather than working with muscle function. Many varieties of TENS devices can be purchased without a prescription for use at home. However, patients are advised to consult with a doctor first, to receive instruction and guidance regarding how to select and use the equipment.

TENS sessions can be helpful in managing pain and discomfort from the following conditions:

  • Arthritis
  • Back or neck problems (including sciatica)
  • Bursitis
  • Carpal tunnel syndrome
  • Fibromyalgia
  • Foot and toe issues (OA, plantar fasciitis, metatarsalgia, bunions, hammer toes, sore arches, peripheral neuropathy)
  • Multiple sclerosis
  • Tendinitis

Both EMS and TENS have been in wide use for decades. When administered by professionals, they are safe and painless and have very few if any side effects. Administered correctly, these techniques can make a difference in pain levels and can aid muscle recovery, relaxation, and rehabilitation.

To find out if you can benefit from this therapy, you should first have an assessment by a physician. People with open wounds or certain health conditions (such as a pacemaker) should not use e-stim or TENS therapy without approval from a doctor.

 

Types of Electrical Stimulation Used in Physical Therapy

If you suffer an injury or illness that results in pain and loss of functional mobility, your healthcare provider may refer you to physical therapy. Your physical therapist will likely work with you to improve your ability to function, and he or she may use various therapeutic modalities to augment your rehabilitation program.

Electrical stimulation is a type of therapeutic treatment that can serve many different purposes in physical therapy. It can be used to decrease pain and inflammation, improve circulation,1 and it can help your muscles contract properly. Electrical stimulation often is used to augment your physical therapy program after an injury or illness; it should not be the only treatment you receive when attending physical therapy.

This list of different types of electrical stimulation can help you understand how it is commonly used in physical therapy. Be sure to ask your physical therapist about your specific needs and gains that are expected when you use electrical stimulation in the physical therapy clinic.

1) TENS

Transcutaneous electrical nerve stimulation (TENS) is a type of electrical stimulation used to help decrease acute and chronic pain.

TENS works by altering or interrupting the pain signals that travel from injured tissues to your brain. It is performed by placing electrodes over the painful part of your body and using electricity to alter pain signals in your brain.

2) Russian Stimulation

Russian stimulation is a form of high-frequency electrical wave stimulation that uses electricity to contract muscle tissue. After injury or surgery, you may be experiencing muscle weakness. Often, muscles are inhibited after an injury and are unable to generate a forceful contraction. Russian stimulation is used to help improve the contraction of your muscles.

3) Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is used much like Russian stimulation. Your physical therapist may use NMES to help your muscles contract properly after injury or surgery.3 This form of muscular re-education can be useful in helping you return to normal function quickly after an injury or surgery.

NMES can also be used to help you perform functional tasks; small switches in the unit can be applied to your body that controls when the stimulation is on or off. When performing a task, like walking, the switch may turn the stimulation on when your leg muscles are supposed to contract, and then turn it off when they are meant to rest.

4) Interferential Current (IFC)

Inferential current (IFC) electrical stimulation is a type of electrical stimulation that your physical therapist may use to help decrease your pain and improve circulation to injured tissues. The IFC works much like TENS, but the current can be easily moved and varied to target your most painful area of injury.

5) High Voltage Stimulation

High-voltage electrical stimulation is a type of electrical stimulation that your physical therapist may use to help decrease your pain or improve circulation. It is also occasionally used to help with wound healing. It is thought that high voltage stimulation helps to change the type of cells near your wound, and this can speed healing.

6) Iontophoresis

Iontophoresis is a type of electrical stimulation used to administer medication into your body through your skin. Medication, such as dexamethasone, can be used to help decrease inflammation, decrease localized swelling, or decrease muscle spasms.5 Some medications used in iontophoresis can also help to decrease calcium deposits and can be used to help manage scar tissue.

While electrical stimulation can be a useful tool to augment your rehab program, you should remember that it is a passive treatment. You do very little while your therapist applies the stim to you. Most successful rehab programs involve an active component of exercise and movement. If your PT recommends you use electrical stimulation in your therapy program, be sure to ask questions and understand what the goal of the stim use is. And always make sure you have an active, self-care exercise program in place to take control of your rehab program.