Studies show that TENS (transcutaneous electrical nerve stimulation) can help reduce pain equally as well as conventional medical drugs can, and in some cases, can even reduce pain more effectively than conventional drugs can.
And unlike with medical drugs, TENS, used correctly, comes with no serious side effects.
When choosing a TENS machine, I would recommend looking for a machine with the following properties:
Has Both High And Low Frequency TENS
High and low frequency TENS reduce pain via different mechanisms, which is why it's theorised that you'd get better results by using both types of TENS. Ideally, you'd get a TENS machine that has a “mixed frequency” mode that switches between high and low frequency TENS.
Has Both TENS And EMS In The Same Device
EMS stands for “electrical muscle stimulation”.
The difference between TENS and EMS is that TENS stimulates SENSORY nerves to prevent pain from reaching the brain. EMS on the other hand, causes muscles to contract.
Although not fully confirmed, some studies suggest that EMS (for certain conditions such as osteoarthritis) may be more effective than TENS at reducing pain.
This is partly because EMS, by focusing on muscle contraction, helps to grow and rehabilitate muscle, while TENS does not.
Has A Wide Range Of Different Modes
Every TENS/EMS device I've seen comes with at least a few different settings/modes that you can switch between. Each mode gives you a different rate and length of pulses, and you have to experiment with different modes to see which gives you the most relief at that particular time. The more modes you have to play with, the better your chances of finding a setting that you find particularly comfortable and helpful for your pain.
Also, after a certain period of time (for me, it's anywhere from 20 to 60 minutes), you may find you get used to a particular mode (a process called “accommodation”, where your nerves become more tolerant to the electrical stimulation). You're likely at this point to find better relief by switching to a different mode. So it's good to have multiple different modes that you are comfortable with.
Some TENS devices have a “modulation mode”, where the device automatically varies the pulse settings to prevent or at least delay accommodation.
Designed By A Reliable Company From A Reliable Country
The vast majority of TENS devices on Amazon are both designed and made in China by Chinese companies. I'm not against Chinese manufacturing in general, if they can do a high quality job for cheaper, then why not get them to do it?
However, I would never recommend buying food products or food supplements that are made in China, because you never know what's really in them. With TENS, you are passing small electrical currents through your body, this can be dangerous if the right quality checks are not in place.
The other thing to note, is that a TENS machine from a company who specialises in TENS machines is more likely to be better than a machine sold buy a generic company like Boots.
My Current Favourite TENS/EMS Machine
I recently bought this TENS/EMS machine from a company called Med-Fit. They're a UK-based company who specialise in TENS/EMS devices. The product itself is made in Taiwan.
What I like about this device is that it has all of the properties I listed above. It has high & low frequency TENS (with mixed frequency modes), has both TENS and EMS, and has 30 different modes, including a “modulation mode” that prevents your body from getting used to the electrical stimulation.
Med-Fit Device Update, 9th of June 2022:
I've had this Med-Fit TENS/EMS device for a couple of months now, and I want to tell you about some of its flaws.
Firstly, this is one of few UK-made TENS machines on the market, so it's safer and more reliable than the countless Chinese brands that have flooded Amazon. Here are some of its faults from my perspective…
Despite there being many different modes to choose from, all of the modes have super long rest intervals. I've currently got the machine on my leg, on EMS setting #28, the electrical stimulation comes on for 9 seconds, and then it's off for a whole 12 seconds. I tried all of the different modes, and they all have super long rest intervals like this.
I'm sure there's some science behind why a long rest interval like this is good for healing, but I much preferred the settings on my old ab builder EMS machine I bought some 20 years ago, which gave you the option of blitzing the crap out of your muscles with rapid bursts or prolonged stimulation and really short rest intervals.
I guess a machine like the Med-Fit must be designed for older people with diseases like osteoarthritis, while my old abs machine was designed for young men who want to build muscle. Despite that, I got much better pain relief for my osteoarthritis using my old abs builder EMS machine. But hey, if you are older, maybe you'll prefer the more gentle approach of the Med-Fit, so you'll have to try it out for yourself.
My other problem is that you can't increase the amplitude during the super-long rest intervals. If you decide the amplitude isn't strong enough, you have to wait that entire 12 seconds for the rest interval to be over before you can increase it. I just want to increase the amplitude and then get on with what I was doing, I don't want to have to stare at the bloody device until the rest interval is over.
Each mode is anywhere from 25 minutes to 30 minutes long. At the end of it, the device automatically stops and resets the amplitude to zero. If you want to continue for longer, you can't just put the amplitude back up, you have to hold the power button for what seems like ages to turn it off, then hold it again to turn it back on, then put the amplitude back up, hoping not to be caught out by a darn rest interval. I know Med-Fit think it's for our own good that we rest between sessions, but shouldn't that be up to the user? I'd much prefer that the machine would continue for at least an hour like my old abs machine did, with maybe a non intrusive alarm or recommendation that we take a break after 20 to 30 minutes, and for there to be a quick single button-push to restart the session after it stops.
That's it, rant over. Due to the above complaints, I much prefer my old abs machine, only I can't recommend it as my current favourite device on this article, because it's a discontinued product.
If you are a younger person and you prefer to have something that will really challenge your muscles, even if it's to reduce joint pain, you might want to look into getting an EMS machine that's built for building muscle, as opposed to something like this Med-Fit one, which is designed to be delicate and easy going. A muscle builder EMS machine will still help reduce pain, only it will give you options for far greater muscle stimulation with shorter rest intervals. You can always reduce the amplitude if you need less stimulation.
I'll update this article when I try out a more modern muscle builder EMS machine, and find that it's better than the Med-Fit.