Tens for muscle

Medically Reviewed By : Dr Sravya, MBBS, MS

What Is Tens?

Muscle pain is one of the most common types of pain experienced by us. It can be caused due to various reasons such as injuries, diseases, overuse of muscles, stress, etc. Muscle pain can be acute or chronic. The pain can be felt as a continuous, deep pain or in short, random bursts. Muscle pain can be generalised, i.e., all over the body, or localised, i.e., in specific areas. Muscles also undergo other painful conditions like spasms or knots. If certain muscles remain unused for a prolonged duration, they may waste away, causing muscle atrophy.

A method, Transcutaneous Electrical Nerve Stimulation or TENS for muscle pain relief is commonly used . In this method, a mild electric current is used to stimulate the nerves in order to provide relief from the pain.

In This Article

How It Works

There are two theories as to how the TENS works for muscle pain relief –

The mild electrical impulses of low voltage stimulate the nerve cells which block the transmission of pain signals to the brain and spinal cord. This reduces pain by relaxing the muscles and changing the body's ability to feel pain.
The electric currents also stimulate the brain to produce hormones known as endorphins. Endorphins are known to be the body’s in-built painkillers. They relieve pain by blocking the neurons which receive pain signals.

The Tens Unit

TENS for muscle pain relief is administered with the help of a TENS unit, which is available over the counter in medical stores. The unit is a small battery-powered device with patches and wires. A TENS unit consists of –

1. How to use the TENS for muscle pain relief –

TENS for muscle pain relief is a commonly used device. So, it can be bought and used without a prescription, but it is always advisable to use it after consulting a doctor or physical therapist. The steps to use the unit are –

The unit must be switched off before starting.
The sticky patches (electrodes) are then placed on the affected areas.
They are connected to the main unit using the lead wires.
The unit is turned on once the patches are firmly placed on the skin.
The unit has controls that can be used to adjust the settings as advised.
Once treatment is done, the machine is switched off, the patches are removed and the wires are disconnected.

2. Electrode Placement

When using TENS for muscle pain relief, it is important to place the electrodes correctly for the treatment to be safe and effective. The electrodes must be placed on skin that is clean, dry, and easily accessible. The skin must be free of any oils, lotions, or creams. It is recommended to wash the area and wipe it dry before placing the electrodes.

The electrodes should not be placed –

On or near the eyes or mouth
Anywhere on the neck
On the temples or forehead
On open wounds or broken skin
Areas of skin with inflammation, infection, or swelling
Directly on or near tumours
Directly on or near reproductive or genital organs
On the chest and upper back areas simultaneously
On skin where sensation is reduced
Directly on the spine
Internally, unless specifically advised and under the supervision of a trained physical therapist.

3. Controls

The controls provided on the TENS unit can be used to adjust the settings as per patient requirements. These settings must be determined by a doctor or a physiotherapist. The intensity, frequency, duration, and type of currents can be altered.

Intensity – The intensity of electric currents can be adjusted using a dial.
Frequency – It is the number of electric currents per second. Two frequencies are commonly used – High-frequency (HF) and Low-frequency (LF).
Duration – It refers to the microseconds for which the current enters the body.
Type – Electric currents can be administered continuously or in bursts.

Frequency	No. of cycles	Used for
High-frequency (HF)	80-120	Acute pain
Low-frequency	1-20	Chronic pain

Tens Techniques

Three different TENS techniques for muscle pain relief are used to administer the treatment according to the type of pain. They are –

1. Conventional TENS –

2. Acupuncture-like (AL) TENS –

3. Intense TENS –

It is a high frequency, high intensity TENS.
It is applied near the area affected by pain.
The patient experiences painful sensations in the area where it is applied.
It is only given for 5-15 minutes at a time.
Out of these, conventional TENS is the most commonly used technique.

Indications

TENS has been widely used for the relief of acute as well as chronic pain. It is commonly used to relieve pain in conditions such as –

Fibromyalgia – Chronic pain condition which causes musculoskeletal pain all over the body, usually accompanied by fatigue.
Arthritis – Condition where joints get inflamed.
Bursitis – Condition where the fluid-filled sacs, known as bursae, which cushion the joints get inflamed.
Oral pain – Pain caused due to temporomandibular joint dysfunction (TMD).
Nerve damage due to diabetes, known as diabetic neuropathy.
Muscle knots
Muscle spasms
Pelvic pain due to endometriosis
Labour pain
Back pain
Neck pain
Pain due to sports injury

Contra-Indications

It is not recommended to use TENS therapy in certain conditions, such as –

Patients with implanted devices such as pacemakers or defibrillators
Pregnancy
Epilepsy
Deep vein thrombosis
Bleeding disorders
Cancer
Heart diseases
Damaged skin due to eczema, dermatitis, etc.

Adverse Effects

Although it is rare to experience severe adverse effects of TENS therapy for muscle pain relief, some side effects may be seen, such as –

Some patients may be allergic to the adhesive used in the electrodes. Redness, swelling, rash, irritation, or itching are possible side effects of these allergies.
Some patients may find the mild tingling sensation brought on by the electric currents to be uncomfortable.
In rare cases, nausea or dizziness may be seen.

Advantages

There are several benefits of TENS therapy that make it a widely used method for muscle pain management, such as –

It is a non-invasive method.
Unlike pain medication, it is non-addictive.
The TENS unit is a small, portable device, which makes usage convenient.
It is a low-risk method.
With regular usage, some patients are able to reduce their medication dosage.
TENS can be used throughout the day without impeding the daily routine.

Limitations

Although TENS is a widely accepted and popular pain relief method, it has some limitations, such as –

With prolonged usage, patients may develop tolerance to the treatment, thus reducing its efficacy.
Some patients complain of discomfort due to the tingling sensations caused by the electrical currents.
TENS might not be effective for all types of pain.
TENS is not a cure for pain, it only provides short-term relief.

Precautions

It is important to follow some precautionary measures to enable safe and effective usage of TENS. These include –

The electrodes must be placed correctly as instructed.
The machine should be switched off before placing, moving, or removing the electrodes.
TENS should never be used while driving or operating heavy machinery.
TENS should not be used while bathing/showering.
The electrode patches should never be shared with anyone else.
TENS must always be used after consulting a doctor or a physical therapist.

Frequently Asked Questions

TENS can be used throughout the day. For relief from chronic pain, it is most beneficial to use it when active.

TENS can be of some use to treat muscle atrophy. However, Electrical Muscle Stimulation (EMS) is more helpful for muscle atrophy.

TENS uses electrical currents to stimulate nerve cells and is mainly used for relief from acute or chronic pain. On the other hand, EMS uses electrical currents to stimulate the muscles and is used for muscle strengthening and rehabilitation.

TENS on its own may be sufficient for pain management in most cases. However, its efficacy is improved when used in conjunction with medication and exercises.