If you are one of millions of Americans who suffer from chronic low back pain there is a good chance that you have tried almost every trick in the book to get rid of the pain.
Traditional remedies generally focus on medications such as ibuprofen and acetaminophen, or using heat or cooling packs. Unfortunately, though, most of these remedies are somewhat limited in their effectiveness and people often find that their low back pain continues to flare up.
It is no wonder then, that many people are left wondering about alternative treatments, such as TENS units for low back pain, and wonder if they might work to help relieve pain and get them mobile again.
What Is A TENS Machine?
A TENS unit is a transcutaneous, electrical nerve stimulator. It works by delivering small electrical impulses to your muscles through electrodes that attach to your skin. It sounds a bit scary but there is some sound science behind this new type of treatment.
The TENS unit basically sends electrical impulses through your body to stimulate your body’s own natural pain-relieving response. These electrical impulses release endorphins that stop pain signals in the brain.
How Does A TENS Machine Work?
TENS units can produce different frequencies which are either low frequencies, or high frequencies. The intensity of the impulse can range from a simple sensory response (where your body just feels pain) to a more intense motor response, where the strength of the impulse can actually cause your body to respond, physically, with an action.
Sensory (or low intensity) signals are where the electrical impulse is strong, but comfortable, and it doesn’t affect your motor system. High intensity impulses are not painful but they often produce a physical reaction from your motor system.
Tolerance Build Up
Having a product that prevents pain without using pharmaceutical products sounds wonderful, and it is, to some extent. Unfortunately, over time, people often build up a tolerance to TENS signals. Studies have found that by day 4 of repeated use, the opioid receptors of the body build up a tolerance to the TENS impulses.
Over the past few years, however, more research has been done to see if, or how, this tolerance build up can be prevented. Researchers have found that blocking certain receptors in the body can delay this tolerance build up by about 5 days.
More studies are trying to see if alternating high and low frequencies (instead of using just one consistent frequency) could delay the onset of tolerance even more.
While the research is promising, it still isn’t the best news for those who are trying to treat low back pain themselves, in a home setting. It also shows that we need more research on this solution as it is a great option to help decrease the use of pharmaceutical solutions for low back pain.
How To Use Different Frequencies
New studies and clinical trials are currently underway to examine the effects of different frequencies on different conditions. TENS can be effective for both chronic and acute pain conditions, it just depends on how you use the stimulation. Both high frequency and low frequency TENS have been shown to reduce pain, especially when they are applied at a strong intensity.
Interestingly, studies have shown that high frequency TENS may be more effective for those individuals taking opioids for their condition. It is important to make sure that you use the strongest intensity possible, while still making it comfortable to the user, so that you can get the effects of hypoalgesia — a reduction in pain sensation.
Current research is indicating that using lower intensity frequencies is often ineffective when trying to treat pain. In fact, using TENS at inadequate intensities is one of the main reasons for the conflicting reports of its effectiveness. It is vitally important to make sure that you use your TENS unit at the maximum tolerated intensity to ensure a good response.
TENS Units For Low Back Pain: Conflicting Results
High-frequency TENS signals seem to be best for acute pain conditions, while low frequency showed positive effects at 32 weeks. A meta-analysis study showed positive effects of TENS for the relief of chronic musculo-skeletal pain, but other back pain studies have not always been able to replicate these results due to poor study designs and small sample sizes.
Clinical Research Around TENS
The lack of research may be a key reason that more studies on TENS mechanisms for individual pain conditions is so important. Potential users need clearer answers on the effectiveness of TENS for low back pain and musculoskeletal conditions.
One of the latest trials was published as recently as 2022. Unfortunately this study was simply a meta study that didn't include any new research - simply a review of of 381 randomly controlled trials. The authors of the study found that "there was moderate-certainty evidence that pain intensity is lower during or immediately after TENS compared with placebo and without serious adverse events".
The authors did note, however, that the levels of evidence were downgraded because all of the trials were small in size and had limited data with poor adverse event reporting. Again, more data, with more robust evidence would help people make a more informed decision about this therapy.
What types of conditions can you use TENS for?
TENS units can help reduce pain in some of the following conditions:
Who Should NOT use a TENS unit?
You should definitely NOT use a TENS unit if you have any of the following:
In-dwelling pumps or monitors
Any implanted metallic or electronic device.
TENS units are a great and inexpensive way to treat low back pain, especially for those wanting to be able to treat their condition at home, or while traveling. TENS units are also a very welcome alternative to using medication to manage low back pain.
If you are considering using a TENS unit for your low back pain, it is important, however, to remember that the data supporting this technique is limited and has not clearly shown consistent results in reducing pain.
When using a TENS machine it is key for you to know how to use intensity and frequency to ensure maximum benefits and also to prevent rapid tolerance build up. And the most important thing to remember, is to always check with your local healthcare provider before starting a new treatment.
This is especially important if you have any sort of electrical medical device implanted in your body, as the signals may interfere with your current medical device and cause other problems.
If you have used a TENS machine to help with your low back pain we would love to hear about your experiences. Feel free to send us a message or share your experience with others on our social pages.