What Does A TENS Unit Do For Muscles? (And What Doesn’t It Do?)

Geoffrey Lions
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Muscle Relaxation / Tight Muscles

TENS stands for “transcutaneous electrical neural stimulation” and refers to a particular type of treatment used to stimulate nerve endings in muscles or nerves to get them to relax.

You might be familiar with the sort of cocoon-like device that’s used to make massage feel more relaxing. If you’ve ever had physical therapy using electrical stimulation, then a TENS unit is what you experienced.

Using a TENS unit is similar to using an ice pack to ease pain, but is more cost conscious. While an ice pack can cool your entire body down, a TENS unit only targets the part of your body that’s hurting.

There is also the TENS unit used during childbirth that provides a similar feeling to “whispering waves”. The combination of both continuous and intermittent electrical pulses is what helps to control pains, mainly during labor.

The TENS unit’s electrical stimulus has a relaxing effect on the nerve fibers leading from the body to the brain. It’s triggered by gentle pulses of electricity through the nerves, sending messages from the body to the brain to relax. The signals for pain are intercepted and blocked.

Muscle Knots

If you’re like most, you’ve definitely dealt with a muscle knot at some point. These areas where the muscle fibers have been pulled taut and formed a knot are so called trigger points, and can cause great discomfort. The good news is, there are ways to address them to relieve the pain, which we will cover a little later.

It’s not uncommon for people to mistakenly refer to a muscle knot as a muscle cramp. While muscle cramps can be caused by muscle knots, they differ in the way muscle knots can have a significant effect on muscle movement. A muscle memory burden can hold them in place, which is why they can persist after a muscle cramp has subsided.

If you’re trying to decide if you have a muscle knot or cramp, try gently stretching the affected area. If there’s no movement or resistance, then it’s likely a muscle knot. If there’s movement with stretching, then it’s likely a muscle cramp.

It’s also important to note that muscle knots and muscle cramps are two different issues. Sufferers of muscle knots often deal with them daily and in many different locations, whereas muscle cramp-only cases are usually isolated.

Muscle Spasms

If the pain in your muscles is caused by muscle spasms, then TENS unit, or transcutaneous electrical nerve stimulation, can relieve your pain. A TENS unit is a battery-powered device that delivers electrical impulses. When you have a muscle spasm, the nerves in your muscles send pain signals to your brain. With the contracting and stretching of your muscle, an electrical current is generated that stimulates your nerves and blocks the pain and inflammation.

A TENS unit does not work by strengthening the muscles, but by blocking the pain signals that trigger the muscle spasms. They don’t provide physical therapy, but you can use it to complement physical therapy.

What does a TENS unit do for muscles? It doesn’t build muscles but gives your muscles a break from pain so they can rest and heal while recovering from injuries and surgery.

Muscle Recovery

There’s been a lot of attention given to TENS (Transcutaneous Electrical Nerve Stimulation) therapy as a way to help speed recovery from muscle aches and pains. In fact, this therapy is used for both acute and chronic pain management.

This phenomenon was first discovered by accident in the 1970s when researchers were studying pain medications. (1) They used electrodes that were connected to a nerve center in the lower back and discovered that they could control the intensity and location of the pain with these electrodes.

In the 1990s, a Swedish company looked into how electrical stimulation of muscles (EMS) helped in healing. They found that a combination of EMS and heat therapy sped up the recovery process after an athlete was injured. (2)

Since then, studies have shown that electrical stimulation of muscles can lower inflammation and soothing the tissue surrounding the site of pain. Electrical stimulation has also been shown to speed up the body’s natural pain blocking chemicals. As a result, the muscle has a better chance of recovering from injuries faster.

The Verdict

TENS stands for Transcutaneous Electrical Nerve Stimulation. It’s sort of like a high-tech, high-end “pain killer”. What it DOESN’T do is fix the underlying problem and it DOESN’T get rid of inflammation which is the catalyst that actually CAUSED your pain!

In fact, if you keep using it too long, it will nullify the good effects you got from it! And, you will wake up in the morning with a worse pain than you had before you went to bed!

This is why you see many long-term users of TENS Units showing a big drop-off in their usage over the years as they eventually realize this limitation and want to get rid of the pain all the time, not just when they are using it.

If your primary source of source of pain relief is a TENS Unit, you may need to consider other treatments.

Back to TENS (Transcutaneous Electrical Nerve Stimulation) units. While they are excellent pain relief after physical therapy, a crushed finger, or an accident, they don’t really fix the underlying problem that’s causing the pain.

Want to find out more?

The TENS unit is a basic device that delivers electrical pulses. It’s great for relieving muscle and joint pain, but the best part is that it’s inexpensive and easy to use.

There are three main types of TENS units available. The least expensive is a single channel machine that delivers a steady frequency pulse to relieve chronic back, neck, shoulder, hip or knee pain. The two- and three-channel machines deliver up to 80 pulses per second. This results in an intense muscle contraction that’s great for treating acute or chronic leg and pelvic pain.

Typically, TENS units require a prescription at a medical supply store or drug store, but they are inexpensive enough to purchase at your local pharmacy.