Electric stimulation, also known as electrical stimulation therapy or electrotherapy, is a non-invasive method used to reduce pain and muscle spasms. The therapy uses electrical impulses to stimulate nerve and muscle activity, resulting in improved blood flow, muscle strength, and reduced pain. Electric stimulation is commonly used in physical therapy and rehabilitation, but it can also be used for chronic pain management and for conditions such as arthritis, fibromyalgia, and neuropathic pain.
Types of Electric Stimulation
There are several types of electric stimulation that are used for pain management, including:
• Transcutaneous Electrical Nerve Stimulation (TENS): This type of stimulation uses low-voltage electrical impulses to stimulate the nerves and reduce pain. TENS is often used for chronic pain, such as back pain, neck pain, and osteoarthritis.
• Interferential Current (IFC): IFC is a type of electric stimulation that uses a higher frequency than TENS. It is used to treat chronic pain conditions such as arthritis, back pain, and muscle spasms.
• High-Voltage Pulsed Current (HVPC): HVPC is a type of electric stimulation that uses high-voltage electrical impulses to stimulate nerve and muscle activity. It is used to treat chronic pain conditions such as fibromyalgia and complex regional pain syndrome.
• Neuromuscular Electrical Stimulation (NMES): NMES is a type of electric stimulation that uses electrical impulses to stimulate muscle activity. It is commonly used in physical therapy and rehabilitation to improve muscle strength and reduce muscle spasms.
How Electric Stimulation Works
Electric stimulation works by sending electrical impulses through electrodes that are placed on the skin near the area of pain. The electrical impulses stimulate nerve and muscle activity, resulting in improved blood flow, muscle strength, and reduced pain.
The specific mechanism by which electric stimulation reduces pain is not well understood, but it is thought to work by blocking the transmission of pain signals from the affected area to the brain. Additionally, the electrical impulses may also stimulate the release of endorphins, the body’s natural pain-relieving chemicals.
Effectiveness of Electric Stimulation
Electric stimulation has been found to be effective in reducing pain and muscle spasms. A number of studies have found that TENS is effective for reducing chronic low back pain, and may be more effective than other forms of pain management such as medication.
Interferential current (IFC) has been shown to be effective in reducing chronic pain, and has been found to be as effective as other forms of pain management such as medication.
High-Voltage Pulsed Current (HVPC) has been found to be effective in reducing pain and muscle spasms in conditions such as fibromyalgia and complex regional pain syndrome.
Neuromuscular Electrical Stimulation (NMES) has been found to be effective in improving muscle strength and reducing muscle spasms.
Safety and Side Effects
Electric stimulation is generally considered safe, but there are some potential side effects, such as:
• Skin irritation: The electrodes used for electric stimulation can cause skin irritation, particularly if they are not properly cleaned and cared for.
• Tingling or numbness: Some people may experience tingling or numbness during electric stimulation, but this is usually temporary and goes away after the stimulation is stopped.
• Muscle soreness: Some people may experience muscle soreness after electric stimulation, but this is usually temporary and goes away after a few days.
It’s important to note that people with certain medical conditions such as pacemaker, pregnant women and people with heart failure.
How TENS Units Work For Pain Management
TENS Units provide non-pharmaceutical pain control which can reduce dependency on pain medications. They are easy for patients to manage and can be worn during everyday activities such as at work and during recreational activities. They are inexpensive and non-addictive.
They are safe and simple to use without the risks associated with surgery or heavy duty narcotic medications. Patients can think clearly without living in a “narcotic fog”, thereby living more actively and productively. The electrical stimulation from TENS machines relieves pain by stimulating peripheral nerves through what is termed the gate control mechanism. The gate control theory of pain suggests that in the spinal cord there is a control mechanism acting as a gate.
The electrical impulses from TENS units, according to this theory, represent a non-noxious input. This input suppresses pain by closing the gate to incoming noxious input, such as pain from an arthritic back. If the gate is closed by non-noxious stimuli, such as that provided by TENS unit (transcutaneous electrical nerve stimuli), then the body will not be able to process the noxious stimuli and pain will be therefore reduced.
There are two types of cells in the area of the spinal cord where signals come into. One is “inhibitory” and the other is “transmission”. Transmission cells are activated by incoming signals and when a critical threshold level is reached, pain starts as the gate opens and the brain receives those signals and processes them as pain. The job of the inhibitory cells is to inhibit activation of the transmission cells, thereby closing the gate and keeping it closed.
The job of a TENS unit is to excite the inhibitory cells and close the gate.
How is a TENS machine used?
TENS machines are small boxes with four wires and electrode pads, through these pads small electronic pulses are sent to activate your body’s natural pain relief reactions. Here is how to use one:
• Attach two of the pads under the line where your bra strap would usually lie and two just above your pants line. Prior to attaching these pads you must apply pre tens preparation gel.
• You can then either attach the clip on your tens machine to a convenient place on your clothing or hold the machine in your hand.
• When you feel a contraction, push the pulse button to send an electronic pulse that will stimulate your body’s natural pain relief reactors.
• Use the dial to adjust the level of the electronic pulses in accordance with how strong your contractions are.
How TENS machines work?
There are two main theories about how they work:
• One theory is that the electrical pulses prevent pain signals from reaching your brain.
• The second theory is that the electrical pulses stimulate endorphins. Endorphins are feel good hormones that can combat pain naturally.
TENS machines will also allow you to have complete control over your pain relief. Achieving a sense of control during childbirth can help you feel more confident, which is a great pain management technique in itself.
When can I begin using my TENS machine?
They can be used at any time during your labour. Unlike forms of pain relief such as birthing pools and epidurals, they will not disturb the dilation process and midwives will recommend that you use them prior to 6cm’s. They can be used at hospital or at home, so no matter where you opt to birth you can be confident that the use of a TENS machine is allowed. If you are choosing a hospital birth it is important that you rent or buy one prior to being admitted to hospital. Many hospitals will not provide a TENS machine upon your arrival as most women are not admitted until they have reached the more established stages of labour where they are able to use other forms of pain relief. That does not mean that you can’t use one throughout your labour, it just means that you should ensure you can provide one for yourself.
What are the advantages of using one?
• They can be used at any point during your labour. They won’t disturb the dilation process unlike birth pools and epidurals, two forms of pain relief that midwives are reluctant to grant prior to 6cms due to the early administration of them increasing the chance of having an assisted birth.
• They can be used in hospital or at home. So if you change your birth plan at the last moment, you won’t have wasted time by buying or renting one.
• You have complete control. Unlike an epidural you have control over when one is used, how long it lasts and there are no lasting side effects. If you do not like it, you don’t have to wait for it to wear off before choosing another form of pain relief.
• They are easy to use. So long as you are given the go ahead to use one after discussing your birth plan with your midwife, you do not need a medical professional around to implement the use of a TENS machine.
• They are portable and none invasive, which is great for women that want to walk around and experience an active labour.
Are There Any Disadvantages?
• If your babies heart needs to be monitored electronically you may not be able to use one.
• They can make it awkward for your partner to massage your back. However this does not have to be a major problem as TENS machines can be removed and re-applied with ease.
• They cannot be used in the bath if you are choosing to bathe to relieve pain. Again, this need not be a major problem, as long as you dry properly before re-applying your TENS you can switch between both forms of pain relief.
• They cannot be used with birthing pools, again this doesn’t have to be a problem as most women use TENS machines in the run up to using a birthing pool as their primary form of pain relief. Much like with a bath, you can switch between the two.
Remember if your TENS machine does not work immediately, you should persist for at least an hour to allow your body to establish its reaction. Even if it fails to work for you that does not mean that you can’t use other forms of pain relief, that’s the beauty of them, they won’t prohibit you from exploring other pain relief options.