- Transcutaneous Electrical Nerve Stimulation (TENS)
- How does transcutaneous electrical nerve stimulation (TENS) work?
- What is transcutaneous electrical nerve stimulation (TENS) therapy used to treat?
- For what types of conditions and areas of the body should transcutaneous electrical nerve stimulation (TENS) therapy not be used?
- TENS (transcutaneous nerve stimulation) for pain relief in labour
- TENS Unit | Definition & Patient Education
- TENS (transcutaneous electrical nerve stimulation)
- Positioning the pads
- Turning it on and adjusting the strength
- What Is Transcutaneous Electrical Nerve Stimulation (TENS) Used for?
- How does transcutaneous electrical nerve stimulation work?
- What are the types of transcutaneous electrical nerve stimulation?
- How is transcutaneous electrical nerve stimulation performed?
- What are the side effects of transcutaneous electrical nerve stimulation?
- Is transcutaneous electrical nerve stimulation safe?
- Can a TENS unit cause nerve damage?
- Is TENS effective for pain?
- TENS unit: Benefits, side effects, and research
- Stimulation intensity
- Electrode placement
- Effectiveness of Transcutaneous Electrical Nerve Stimulation for Treatment of Hyperalgesia and Pain
Transcutaneous Electrical Nerve Stimulation (TENS)
Transcutaneous electrical nerve stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain. A small device delivers the current at or near nerves. TENS therapy blocks or changes your perception of pain.
Transcutaneous electrical nerve stimulation (TENS) is a therapy that uses low voltage electrical current to provide pain relief. A TENS unit consists of a battery-powered device that delivers electrical impulses through electrodes placed on the surface of your skin.
The electrodes are placed at or near nerves where the pain is located or at trigger points.
How does transcutaneous electrical nerve stimulation (TENS) work?
There are two theories about how transcutaneous electrical nerve stimulation (TENS) works.
One theory is that the electric current stimulates nerve cells that block the transmission of pain signals, modifying your perception of pain.
The other theory is that nerve stimulation raises the level of endorphins, which are the body’s natural pain-killing chemical. The endorphins then block the perception of pain.
What is transcutaneous electrical nerve stimulation (TENS) therapy used to treat?
TENS therapy has been used or is being studied to relieve both chronic (long lasting) and acute (short-term) pain. Some of the most common conditions for which TENS has been used include:
For what types of conditions and areas of the body should transcutaneous electrical nerve stimulation (TENS) therapy not be used?
Do not use TENS therapy at these specific body locations if you have any of the following conditions:
- An implantable device (cardioverter/defibrillator, neurostimulators, bone growth stimulator, indwelling blood pressure monitors). Do not use TENS therapy over or close to the areas where an electronic device is implanted. TENS could cause these devices to malfunction.
- Are pregnant. Do not apply TENS therapy to the abdomen; pelvic area; lower back; or to acupuncture points at the knee, hand or ankle. (However, TENS can be used for labor pain.)
- Cancer. Do not apply electrodes to areas of the body where there is known or suspected cancer. Do not use TENS if you have undiagnosed pain and a history of cancer in the last 5 years.
- Epilepsy. Do not apply electrodes to your head, neck or shoulders. The impulses could cause seizures.
- Deep vein thrombosis or thrombophlebitis. Do not use TENS therapy as it may increase blood circulation, which may increase the risk of dislodging a blood clot.
- A bleeding (hemorrhagic) disorder or recent or actively bleeding tissue. TENS therapy could increase bleeding at the tissue site or increase the risk of bleeding in persons with bleeding disorders.
- Heart disease. Do not apply TENS therapy to the chest if you have heart disease, heart failure or arrhythmias.
In addition, TENS should not be applied:
- To infected tissues, wounds due to osteomyelitis or if you have tuberculosis. TENS therapy may result in the spread of infections.
- To areas of tissue that have been recently treated with radiation.
- To damaged skin (Except for open wounds where the intent is to use electrical stimulation to heal tissue. In these cases, therapy should be guided by a skilled therapist.)
- Near or over eyes or mouth, front or side of neck, or on the head.
- Near reproductive organs or genitals.
- To areas of the body that lack or have reduced sensation.
- In persons who have trouble communicating or who have mental impairment and cannot provide feedback to ensure the safe use of TENS.
If you have any current or past health issues, or any concerns or questions, always check with your healthcare provider before using TENS.
Last reviewed by a Cleveland Clinic medical professional on 01/15/2020.
TENS (transcutaneous nerve stimulation) for pain relief in labour
TENS is a device that emits low-voltage currents and which has been used for pain relief in labour. The way that TENS works is not well understood. The electrical pulses are thought to stimulate nerve pathways in the spinal cord which block the transmission of pain.
In labour the electrodes from the TENS machine are usually attached to the lower back (and women themselves control the electrical currents using a hand-held device) but TENS can also be applied to acupuncture points or directly to the head. The purpose of the review was to see whether TENS is effective in relieving pain in labour.
The review includes results from 17 studies with a total of 1466 women. Thirteen studies examined TENS applied to the back, two to acupuncture points and two to the cranium (head). Results show that pain scores were similar in women using TENS and in control groups.
There was some evidence that women using TENS were less ly to rate their pain as severe but results were not consistent. Many women said they would be willing to use TENS again in a future labour. TENS did not seem have an effect on the length of labour, interventions in labour, or the well-being of mothers and babies.
It is not known whether TENS would help women to manage pain at home in early labour. Although it is not clear that it reduces pain, women should have the choice of using TENS in labour if they think it will be helpful.
There is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact (either positive or negative) on other outcomes for mothers or babies. The use of TENS at home in early labour has not been evaluated. TENS is widely available in hospital settings and women should have the choice of using it in labour.
Read the full abstract…
Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity.
During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain.
TENS machines are frequently operated by women, which may increase a sense of control in labour.
To assess the effects of TENS on pain in labour.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and reference lists of retrieved papers.
Randomised controlled trials comparing women receiving TENS for pain management in labour versus routine care, alternative non-pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines.
Data collection and analysis:
Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies.
Seventeen trials with 1466 women contribute data to the review. Thirteen examined TENS applied to the back, two to acupuncture points, and two to the cranium.
Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less ly to report severe pain (average risk ratio 0.41, 95% confidence interval 0.31 to 0.54; measured in two studies).
The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain.
There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No adverse events were reported.
TENS Unit | Definition & Patient Education
A transcutaneous electrical nerve stimulation (TENS) unit is a device that sends small electrical currents to targeted body parts. These currents are used to relieve pain. Some TENS units are designed for use in a hospital or healthcare facility. Others are safe to use at home.
TENS therapy subdues hyperalgesia, which is a high sensitivity to pain. The pain may be located anywhere on the body.
A TENS unit sends electrical pulses through the skin. These pulses control pain signals in the body, creating temporary or permanent relief from pain. They can control abnormally excited nerves and release endorphins.
TENS therapy is used for many conditions, including:
It’s also used for injuries and wounds.
TENS therapy is considered mostly safe. On rare occasions, an electrical current will be too intense for a patient, causing burning or irritation on the skin.
The effect of TENS on fetuses is unknown at this time. Pregnant women should not use electrical stimulation for pain relief. People with heart conditions should use caution as well.
Some people with skin allergies may react to the electrode pads used with the units. People with pacemakers, infusion pumps, defibrillators, or similar devices shouldn’t be exposed to the electrical currents produced by a TENS unit.
A TENS unit is an electrical device that sends low-voltage currents into the body. Electrode pads are placed over specific nerves on the body to conduct the currents from the unit to the nerves.
The frequency of the currents coming from a TENS unit can be turned up or down, ranging from about 10 Hz to 50 Hz. Most sessions with a TENS unit last less than 15 minutes and can be administered as often as needed.
Transcutaneous electrical nerve stimulation is considered highly effective in controlling pain. It can reduce the feelings of pain and prevent them from coming back in the future.
There is no preparation necessary for a TENS unit. Electrodes are placed on the surface of the skin, above the overactive nerves. For home devices, a patient will need to know where these pads go, but the doctor will place them in a healthcare setting.
Transcutaneous electrical nerve stimulation may result in instant and possibly prolonged pain relief. Through the release of endorphins and the control of nerves, TENS sends relief directly to the site of pain.
Some people experience permanent pain relief after repeated sessions with a TENS unit. Others need TENS therapy for a prolonged period of time. The effectiveness ranges by condition and intensity of treatment.
TENS devices send small electrical currents to parts of the body to control pain signals, creating temporary or permanent relief.
The effectiveness of TENS treatment varies depending on what condition you’re treating, and how intense the treatment is. The treatment may be conducted in a healthcare setting, or you may be able to use a device in your home.
Before starting this treatment, be sure to discuss any questions you may have with your healthcare provider.
Can a TENS unit be used for pain in your jaw from oral surgery?
Anonymous Healthline reader
TENS therapy may be a helpful treatment option for pain. However, it isn’t very clear which specific medical conditions TENS units are most effective at treating.
Given the lack of studies that clearly address the applicability and effectiveness of TENS units for postsurgical jaw pain in particular, it would be best to discuss using a TENS unit for this type of pain with your oral surgeon and pain physician.
Euna Chi, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
TENS (transcutaneous electrical nerve stimulation)
Transcutaneous electrical nerve stimulation (TENS) is a method of pain relief involving the use of a mild electrical current.
A TENS machine is a small, battery-operated device that has leads connected to sticky pads called electrodes.
You attach the pads directly to your skin. When the machine is switched on, small electrical impulses are delivered to the affected area of your body, which you feel as a tingling sensation.
The electrical impulses can reduce the pain signals going to the spinal cord and brain, which may help relieve pain and relax muscles. They may also stimulate the production of endorphins, which are the body's natural painkillers.
TENS may be able to help reduce pain and muscle spasms caused by a wide range of conditions including:
It's also sometimes used as a method of pain relief during labour.
There isn't enough good-quality scientific evidence to say for sure whether TENS is a reliable method of pain relief. More research is needed and clinical trials for TENS are ongoing.
Healthcare professionals have reported that it seems to help some people, although how well it works depends on the individual and the condition being treated.
TENS isn't a cure for pain and often only provides short-term relief while the TENS machine is being used.
However, the treatment is generally very safe and you may feel it's worth trying instead of, or in addition to, the usual medical treatments.
If you're thinking about trying TENS, it's a good idea to speak to your GP about a referral to a physiotherapist or pain clinic.
A physiotherapist or pain specialist may be able to loan you a TENS machine for a short period if they think it could help.
You can choose to buy your own TENS machine without getting medical advice, but it's generally better to have a proper assessment first, so you can find out whether a TENS machine is appropriate for you and be taught how to use it properly.
To get the most benefit from TENS, it's important that the settings are adjusted correctly for you and your individual condition.
If you find TENS effective, you can buy a TENS machine from a pharmacy. They range in price from about £10 to £200. More expensive machines aren't necessarily any better than lower-priced ones, so it's best to do some research before you buy.
The information below is a general guide on how to use a TENS machine. You should always follow the manufacturer's specific instructions.
TENS machines are small and lightweight, so you can use them while you're working or on the move. You can put it in your pocket, clip it to your belt or hold it in your hand.
You can use TENS throughout the day for as long as you , although it shouldn't be used while you're driving, operating machinery, or in the bath or shower.
Positioning the pads
Make sure the machine is switched off before you attach the pads to your skin. Position the pads either side of the painful area, at least 2.5cm (1 inch) apart.
Never place the pads over:
- the front or sides of your neck
- your temples
- your mouth or eyes
- your chest and upper back at the same time
- irritated, infected or broken skin
- varicose veins
- numb areas
Turning it on and adjusting the strength
Turn on the TENS machine when the pads are attached in the correct places. You'll feel a slight tingling sensation pass through your skin.
The machine has a dial that allows you to control the strength of the electrical impulses.
Start on a low setting and gradually increase it until the sensation feels strong but comfortable. If the tingling sensation starts to feel painful or uncomfortable, reduce it slightly.
Switch the TENS machine off after you've finished using it and remove the electrodes from your skin.
For most people, TENS is a safe treatment with no side effects.
Some people may be allergic to the pads and their skin may become red and irritated, but special pads for people with allergies are available.
TENS isn't safe for everyone to use. Don't use it without first seeking medical advice if:
- you have a pacemaker or another type of electrical or metal implant in your body
- you're pregnant, or there's a chance you might be pregnant – TENS may not be recommended early in pregnancy
- you have epilepsy or a heart problem
What Is Transcutaneous Electrical Nerve Stimulation (TENS) Used for?
Transcutaneous electrical nerve stimulation (TENS) is a therapy that provides short-term pain relief using low-voltage electric current. It is noninvasive, inexpensive and can even be self-administered. It is one of the most popular forms of electric therapy for pain relief.
How does transcutaneous electrical nerve stimulation work?
The TENS device delivers electrical impulses through the skin to the nerves. This reduces the ability of the nerves to send pain signals from an injured area to the brain, relaxes the muscles, and provides temporary pain relief.
What are the types of transcutaneous electrical nerve stimulation?
There are three methods by which TENS maybe applied:
- Conventional TENS – high frequency/low intensity stimulation
- Acupuncture- TENS – low frequency/high intensity
- Pulsed or intense TENS – the nerve stimulation comes in short bursts
Conventional TENS is the most commonly used method. The pain relief is almost immediate, but for a short duration. Some patients may not tolerate the higher intensities. These levels are only for those who do not respond to conventional TENS.
How is transcutaneous electrical nerve stimulation performed?
A patient undergoing TENS needs no preparation before the procedure. It can be done at an outpatient facility or at home by the patients themselves.
- The TENS unit is a small battery-operated device that delivers low voltage electric pulses.
- It has electrodes with sticky pads, which are placed on the patient’s skin over the affected area.
- The stimulation settings can be adjusted to give effective pain relief without discomfort.
The TENS sessions can be as long and as often as needed depending upon the method used.
Rheumatoid Arthritis (RA) Exercises Slideshow: Joint-Friendly Fitness Routines See Slideshow
What are the side effects of transcutaneous electrical nerve stimulation?
TENS has few or no side effects on most people. In some patients it may cause a few side effects:
Skin reactions can often be avoided by keeping the gel pads sanitized and following good skin care. The other reactions are uncommon and can generally be relieved with over-the-counter medicines.
TENS should be used with caution on patients with skin allergies or diseases. It should not be used on a patient who
- has a pacemaker or other heart problems,
- is pregnant, or
- has epilepsy.
Is transcutaneous electrical nerve stimulation safe?
TENS is, in general, safe for most people. The electric impulses might cause a prickling sensation that might be uncomfortable for some. Some may be allergic to the electrode pads.
Can a TENS unit cause nerve damage?
TENS unit is not known to cause any nerve damage. A backfire in the TENS unit might provoke an overreaction in the nerve causing some pain or discomfort, but the nerve itself is unly to be damaged. There is no conclusive evidence, but some research suggests chronic electrical stimulation might damage the nerve structure and disturb its function.
Is TENS effective for pain?
Overall TENS is effective for pain relief, which may be instant and prolonged. In some, it may take several sessions to see results. It should also be noted that TENS offers only short-term pain relief and is not a cure for pain.
Clinical experience shows that TENS is effective for most chronic pain and some acute pain. The efficacy of TENS appears to be variable depending on the individuals and the kind of conditions treated. Though many patients experience relief with TENS, no clear scientific evidence shows that it's as reliable a method of pain reduction as painkilling drugs. Research is ongoing.
Medically Reviewed on 3/10/2020
TENS unit: Benefits, side effects, and research
If you buy something through a link on this page, we may earn a small commission. How this works.
A transcutaneous electrical nerve stimulation (TENS) unit is a battery-operated device that some people use to treat pain.
TENS units work by delivering small electrical impulses through electrodes that have adhesive pads to attach them to a person’s skin.
These electrical impulses flood the nervous system, reducing its ability to transmit pain signals to the spinal cord and brain.
The same electrical impulses also stimulate the body to produce natural pain relievers called endorphins.
In this article, learn more about the uses of a TENS machine and the research on its effectiveness.
Share on PinterestTENS units can help treat and manage pain.
TENS units may help treat the following symptoms:
- period pain
- labor pain
- postoperative pain
- joint pain
- neck and back pain
They may also alleviate pain that results from the following conditions:
A TENS unit has controls that allow people to administer an appropriate level of pain relief. People can achieve this by altering the following aspects of the electrical current:
Intensity: A dial allows the user to adjust the intensity of the electrical stimulation.
Frequency: The frequency refers to the number of electrical pulses per second. High-frequency (HF) pulses range from 80 to 120 cycles per second and may help manage acute pain. Low-frequency (LF) pulses range from 1 to 20 cycles per second and are suitable for the treatment of chronic pain.
Duration: The duration is the number of microseconds that the current enters the skin for during each pulse.
TENS is a noninvasive method for relieving pain. People who experience pain relief from TENS may be able to reduce their intake of pain medications, some of which can be addictive or cause adverse side effects.
TENS units are also convenient because they are small, portable, and relatively discrete. People can carry a TENS unit in their pocket or clip it onto a belt to ensure that they have immediate access to pain relief throughout the day.
Share on PinterestIf the adhesive pads cause redness or irritation, hypoallergenic pads are available.
It is safe for most people to use a TENS unit, and they will not usually experience any side effects.
However, the electrical impulses that a TENS unit produces may cause a buzzing, tingling, or prickling sensation, which some people may find uncomfortable.
Some people may be allergic to the adhesive pads. Anyone who experiences skin redness and irritation can switch to using hypoallergenic ones instead.
It is vital never to place the electrodes on either the front of the neck or the eyes. Putting electrodes on the neck can lower blood pressure and cause spasms. On the eyes, the electrodes can increase pressure within the eye and possibly cause an injury.
Although it is safe for most people, experts recommend that some groups of people avoid TENS treatment unless a doctor advises its use.
This recommendation applies to the following people:
- Pregnant women: Pregnant women should avoid using TENS in the abdominal and pelvic regions.
- People with epilepsy: Applying electrodes to the head or neck of people with epilepsy may induce seizures.
- People with heart problems.
- People with a pacemaker or another type of electrical or metal implant.
Due to a lack of high-quality research and clinical trials, researchers have not yet determined whether TENS is a reliable treatment for pain relief.
One study found that TENS treatment provided temporary pain relief for people with fibromyalgia while the machine was in use.
While there is a lack of strong clinical evidence for its effectiveness, TENS is a low-risk pain relief option for many people.
Several factors may influence the effectiveness of TENS:
Research shows that people who use a TENS unit on a daily basis at the same frequency and intensity can develop a tolerance to the treatment.
A person who develops tolerance will no longer feel the same level of pain relief that they did when they first used the unit.
To prevent this from occurring, people can alternate between LF and HF TENS within each treatment session.
Alternatively, they can gradually increase the intensity or duration of TENS on a daily basis.
The range of intensities of the electrical stimulation may account for some of the differences in research findings.
According to a 2014 review, HF TENS treats pain more effectively than LF TENS. In fact, many studies have found LF TENS to be ineffective.
Given that HF TENS is a more effective pain reliever, experts recommend that people apply the highest-intensity TENS that they can tolerate.
TENS may be more effective if people place the electrodes on acupuncture points.
Acupuncture is a practice that uses needles to stimulate the nerves beneath the skin at specific locations known as acupuncture points. Experts believe that this assists the body in producing endorphins.
One review found some evidence that people who receive TENS through acupuncture points may experience a reduction in pain.
The duration of pain relief after using a TENS unit can vary. Some people report that their pain returns as soon as they switch off the device. Others continue to experience an adequate level of pain relief for up to 24 hours.
A 2012 review suggests that the duration of pain relief increases after repeated TENS treatments. However, this repetition can also increase the lihood of a person building up a tolerance to the treatment.
The research on using a TENS unit for pain relief has so far yielded inconsistent results due to a lack of high-quality scientific studies and clinical trials.
Some research suggests that TENS treatment can relieve pain, but this may be dependent on certain factors, such as the affected area of the body and the treatment intensity. Knowing how these factors affect TENS can help people use it more effectively.
Most people can use a TENS unit safely, and few will experience side effects. However, it is best to speak to a doctor before trying TENS either as an alternative treatment or in combination with other methods of pain management.
TENS units are available to purchase at some pharmacies and online.
Effectiveness of Transcutaneous Electrical Nerve Stimulation for Treatment of Hyperalgesia and Pain
Papers of particular interest, published recently, have been highlighted as:
• Of importance
•• Of major importance
1•. Sluka KA. The Neurobiology of pain and foundations for electrical stimulation. In: Robinson AJ, Snyder-Mackler L, editors. Clinical Electrophysiology. Lippincott Williams & Wilkins; Philadelphia: 2008. pp. 107–149.
[• Of importanceA recent review of all the basic science mechanisms underlying TENS] [Google Scholar]
2. Sluka KA, Deacon M, Stibal A, et al. Spinal blockade of opioid receptors prevents the analgesia produced by TENS in arthritic rats. J Pharmacol Exp Ther. 1999;289:840–846. [PubMed] [Google Scholar]
3. Kalra A, Urban MO, Sluka KA. Blockade of opioid receptors in rostral ventral medulla prevents antihyperalgesia produced by transcutaneous electrical nerve stimulation (TENS). J Pharmacol Exp Ther. 2001;298:257–263. [PubMed] [Google Scholar]
4. Sluka KA, Chandran P. Enhanced reduction in hyperalgesia by combined administration of clonidine and TENS. Pain. 2002;100:183–190. [PubMed] [Google Scholar]
5. Loeser JD, Treede RD. The Kyoto protocol of IASP Basic Pain Terminology. Pain. 2008 (in press) [PubMed] [Google Scholar]
6•. Sluka KA, Lisi TL, Westlund KN. Increased release of serotonin in the spinal cord during low, but not high, frequency transcutaneous electric nerve stimulation in rats with joint inflammation. Arch Phys Med Rehabil. 2006;87:1137–1140.
[• Of importanceThis article shows that there is an increase in serotonin in the spinal cord during low-frequency, but not high-frequency, TENS using microdialysis and high-performance liquid chromatography analysis in an animal model of joint inflammation] [PMC free article] [PubMed] [Google Scholar]
7. King EW, Audette K, Athman GA, et al. Transcutaneous electrical nerve stimulation activates peripherally located alpha-2A adrenergic receptors. Pain. 2005;115:364–373. [PubMed] [Google Scholar]
8•. Radhakrishnan R, Sluka KA. Deep tissue afferents, but not cutaneous afferents, mediate transcutaneous electrical nerve stimulation-Induced antihyperalgesia. J Pain. 2005;6:673–680.
[• Of importanceThis article demonstrates the importance of afferents from deep tissues in producing the analgesia produced by TENS by differential anesthetic blockade of the joint or the skin during the TENS stimulation] [PubMed] [Google Scholar]
9. Vance CG, Radhakrishnan R, Skyba DA, et al. Transcutaneous electrical nerve stimulation at both high and low frequencies reduces primary hyperalgesia in rats with joint inflammation in a time-dependent manner. Phys Ther. 2007;87:44–51. [PubMed] [Google Scholar]
10. Sabino GS, Santos CM, Francischi JN, et al. Release of endogenous opioids following transcutaneous electric nerve stimulation in an experimental model of acute inflammatory pain. J Pain. 2008;9:157–163. [PubMed] [Google Scholar]
11•. Ainsworth L, Budelier K, Clinesmith M, et al. Transcutaneous electrical nerve stimulation (TENS) reduces chronic hyperalgesia induced by muscle inflammation. Pain. 2006;120:182–187.
[• Of importanceApplication of TENS over an inflamed muscle in rats reverses the hyperalgesia bilaterally.
Furthermore, application of TENS to the contralateral “mirror side” also reverses the hyperalgesia bilaterally] [PubMed] [Google Scholar]
12. Somers DL, Clemente FR. Transcutaneous electrical nerve stimulation for the management of neuropathic pain: the effects of frequency and electrode position on prevention of allodynia in a rat model of complex regional pain syndrome type II. Phys Ther. 2006;86:698–709. [PubMed] [Google Scholar]
13. Hingne PM, Sluka KA. Differences in waveform characteristics have no effect on the anti-hyperalgesia produced by transcutaneous electrical nerve stimulation (TENS) in rats with joint inflammation. J Pain. 2007;8:251–255. [PubMed] [Google Scholar]
14•. Maeda Y, Lisi TL, Vance CG, et al. Release of GABA and activation of GABA(A) in the spinal cord mediates the effects of TENS in rats. Brain Res. 2007;1136:43–50.
[• Of importanceGABA is released and activates spinal GABA receptors to produce the analgesia produced by TENS] [PMC free article] [PubMed] [Google Scholar]
15•. Sluka KA, Vance CG, Lisi TL. High-frequency, but not low-frequency, transcutaneous electrical nerve stimulation reduces aspartate and glutamate release in the spinal cord dorsal horn.
J Neurochem. 2005;95:1794–1801.
[• Of importanceHigh-frequency TENS reduces the release of excitatory neurotransmitters in the spinal cord through activation of δ-opioid receptors] [PubMed] [Google Scholar]
16. DeSantana JM, Sluka KA. Antinociceptive effect of transcutaneous electric nerve stimulation (TENS) is mediated by ventrolateral periaqueductal grey (vlPAG).. Presented at the XII World Congress in Pain.; Glasgow, Scotland. August 17−22, 2008. [Google Scholar]
17. Chandran P, Sluka KA. Development of opioid tolerance with repeated transcutaneous electrical nerve stimulation administration. Pain. 2003;102:195–201. [PubMed] [Google Scholar]
18•. Hingne PM, Sluka KA. Blockade of NMDA receptors prevents analgesic tolerance to repeated transcutaneous electrical nerve stimulation (TENS) in rats. J Pain. 2008;9:217–225.
[• Of importanceThis article shows that tolerance to repeated application of TENS can be prevented by blockade of NMDA glutamate receptors during the TENS application when the drug is administered systemically.
Systemic blockade of NMDA glutamate receptors also prevents cross-tolerance in the spinal cord] [PMC free article] [PubMed] [Google Scholar]
19. DeSantana JM, Sluka KA. Blockade of cholecystokinin receptors prevents the development of analgesic tolerance to transcutaneous electric nerve stimulation (TENS).. Presented at the XII World Congress in Pain.; Glasgow, Scotland. August 17−22, 2008. [Google Scholar]
20•. DeSantana JM, Santana-Filho VJ, Sluka KA. Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats. Arch Phys Med Rehabil. 2008;89:754–760.
[• Of importanceModulating high- and low-frequency TENS delays the development of tolerance effect] [PMC free article] [PubMed] [Google Scholar]
21•. Brown L, Tabasam G, Bjordal JM, et al.
An investigation into the effect of electrode placement of transcutaneous electrical nerve stimulation (TENS) on experimentally induced ischemic pain in healthy human participants. Clin J Pain. 2007;23:735–743.
[• Of importanceThis article showed no significant differences between two TENS eclectrode placement sites using experimental pain] [PubMed] [Google Scholar]
22. Aarskog R, Johnson MI, Demmink JH, et al. Is mechanical pain threshold after transcutaneous electrical nerve stimulation (TENS) increased locally and unilaterally? A randomized placebo-controlled trial in healthy subjects. Physiother Res Int. 2007;12:251–263. [PubMed] [Google Scholar]
23•. Claydon LS, Chesterton LS, Barlas P, Sim J. Effects of simultaneous dual-site TENS stimulation on experimental pain. Eur J Pain. 2008;12:696–704.
[• Of importanceHigh-intensity (irrespective of the applied frequency) is a key parameter in TENS applications] [PubMed] [Google Scholar]
24. Buonocore M, Camuzzini N. Increase of the heat pain threshold during and after high-frequency transcutaneous peripheral nerve stimulation in a group of normal subjects. Europa Medicophysica. 2007;43:155–160. [PubMed] [Google Scholar]
25•. Tong KC, Lo SK, Cheing GL. Alternating frequencies of transcutaneous electric nerve stimulation: does it produce greater analgesic effects on mechanical and thermal pain thresholds? Arch Phys Med Rehabil. 2007;88:1344–1349.
[• Of importanceThis article demonstrates the superior hypoalgesic effect of mixed TENS frequencies] [PubMed] [Google Scholar]
26•. Oosterhof J, Samwel HJ, de Boo TM, et al. Predicting outcome of TENS in chronic pain: A prospective, randomized, placebo controlled trial. Pain. 2008;136:11–20.
[• Of importancePredicting the effect of high-frequency TENS in chronic pain depends on the choice of outcome measure, and source of pain influences patients’ satisfaction with treatment result] [PubMed] [Google Scholar]
27•. Warke K, Al-Smadi J, Baxter D, et al.
Efficacy of transcutaneous electrical nerve stimulation (TENS) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial. Clin J Pain.
[• Of importanceThis article demonstrates the effect of TENS for chronic low-back pain in multiple sclerosis patients] [PubMed] [Google Scholar]
28•. Mora B, Giorni E, Dobrovits M, et al. Transcutaneous electrical nerve stimulation: an effective treatment for pain caused by renal colic in emergency care. J Urol. 2006;175:1737–1741.
[• Of importanceThis article demonstrates the hypoalgesic effect of local TENS for renal colic pain] [PubMed] [Google Scholar]
29•. Lang T, Barker R, Steinlechner B, et al. TENS relieves acute posttraumatic hip pain during emergency transport. J Trauma. 2007;62:184–188.
[• Of importanceThis article demonstrates the hypoalgesic effect of TENS for emergency pain conditions during transportation to the hospital] [PubMed] [Google Scholar]
30•. Defrin R, Ariel E, Peretz C. Segmental noxious versus innocuous electrical stimulation for chronic pain relief and the effect of fading sensation during treatment. Pain. 2005;115:152–160.
[• Of importanceThis article demonstrates the hypoalgesic effects of interferential current for chronic OA knee pain, where segmental noxious stimulation produces a stronger analgesic effect than segmental innocuous stimulation] [PubMed] [Google Scholar]
31•. DeSantana JM, Santana-Filho VJ, Guerra DR, et al. Hypoalgesic effect of the transcutaneous electrical nerve stimulation following inguinal herniorrhaphy: a randomized, controlled trial. J Pain. 2008;9:623–629.
[• Of importanceThis article demonstrates that TENS significantly decreases analgesic requirements and incisional pain intensity after inquinal herniorrhaphy when compared with placebo] [PubMed] [Google Scholar]
32•. DeSantana JM, Sluka KA, Lauretti GR. High and low frequency TENS reduce postoperative pain intensity after laparoscopic sterilization for tubal ligation: a randomized controlled trial. Clin J Pain. 2008 (in press)
[• Of importanceBoth high- and low-frequency TENS significantly reduce pain after laparoscopic tubal ligation] [PubMed] [Google Scholar]
33•. Cipriano G, Carvalho AC, Bernardelli GF, et al. Short-term transcutaneous electrical nerve stimulation after cardiac surgery: effect on pain, pulmonary function, and electrical muscle activity.
Interact CardioVasc Thorac Surg. 2008;7:539–543.
[• Of importanceTENS significantly decreases incisional pain and improves pulmonary function when compared with placebo after cardiac surgery] [PubMed] [Google Scholar]
34•. Solak O, Turna A, Pekcolaklar A, et al. Transcutaneous electric nerve stimulation for the treatment of postthoracotomy pain: a randomized prospective study. Thorac Cardiov Surg. 2007;55:182–185.
[• Of importanceTENS, used 30 minutes daily, significantly decreases incisional pain and analgesic requirements but not pulmonary function compared with placebo after thoracotomy] [PubMed] [Google Scholar]
35•. Erdogan M, Erdogan AE, Erbil N, et al. Prospective, randomized, placebo-controlled study of the effect of TENS on postthoractomy pain and pulmonary function. World J Surg. 2005;29:1563–1570.
[• Of importanceHigher TENS dosing significantly decreases pain and analgesic requirements and significantly increases pulmonary function compared with placebo after thoracotomy] [PubMed] [Google Scholar]
36. Cheing GL, Hui-Chan CW. Transcutaneous electrical nerve stimulation: nonparallel antinociceptive effects on chronic clinical pain and acute experimental pain. Arch Phys Med Rehabil. 1999;80:305–312. [PubMed] [Google Scholar]
37. Deyo RA, Walsh NE, Martin DC, et al. A controlled trial of transcutaneous electrical stimulation (TENS) and exercise for chronic low back pain. N Engl J Med. 1990;322:1627–1634. [PubMed] [Google Scholar]
38•. Khadilkar A, Milne S, Brosseau L, et al. Transcutaneous electrical nerve stimulation (TENS) for chronic low-back pain. Cochrane Database System Rev. 2005;(3)
[• Of importanceSystematic review of clinical trials on TENS for chronic low back pain] [PubMed] [Google Scholar]
39•. Johnson M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain. 2007;130:157–165.
[• Of importanceA Meta-analysis that shows that electrical stimulation is superior to placebo for chronic musculoskeletal pain] [PubMed] [Google Scholar]
40. Chen C, Tabasam G, Johnson MI. Does the pulse frequency of transcutaneous electrical nerve stimulation (TENS) influence hypoalgesia? A systematic review of studies using experimental pain and healthy human participants. Physiotherapy. 2008;94:11–20. [Google Scholar]