You should be well-informed, when purchasing a TENS unit, since these devices can have a life-span of up to 5 to 10 years. I recommend understanding the basics of how a TENS unit works before making a decision.
What is TENS unit?
A TENS unit is a medical device primarily aimed at inducing pain relief through the use of mild electrical impulses. This stands in contrast with painkillers, which achieve a similar effect with chemical means. The TENS impulses affect the sensory nerves through special electrodes bonded to the skin. The electrical impulses emitted by the TENS unit create a "pinching" feeling, which gets stronger when the current is increased.
Different frequencies of TENS current have different effects on your body!
- High frequencies have a direct pain relieving effect. They stop the transmission of pain signals between the painful area of your body, and your brain. They do this by tiring your nerve pathways, which stop the transmission of pain.
- Low frequencies do not have a direct pain-relieving effect, but instead increase the production of endorphins in your body. These substances are the natural analgesics of the body.
What kind of pains can TENS treatment help reduce?
- neck and back pain, including discushernia, lumbago, sciatica
- muscle injury (bruising, sprain, etc.)
- joint problems
- tendon inflammation (Achilles, Carpal-Tunnel Syndrome)
- diabetic neuropathic pain
- post-operative pains
- menstrual complaints
- pelvic pain caused by endometriosis
The TENS unit can be used alone or as complementary therapy to other analgesic methods. The effects may add up, meaning as fewer medication may be needed.
One of the main indicator of performance of a TENS device, is how many “channels” it has
As previously mentioned, a TENS device provides a pain relieving effect through electrical signals. These signals are transmitted to your body from the device via adhesive electrodes, which are in turn connected to the device via cables. One pair of electrodes connected to the device via one cable refers to one treatment channel.
The performance of a TENS device can be judged by the number of treatment channels it offers. For home use, 1, 2 and 4 channel devices are available. A 1 channel device can power 2 electrodes, a 2 channel device power 4, while top of the line 4 channel devices can work with 8 electrodes at a time.
The main benefit is that the more channels the device has, the larger the area you can handle once. The pain relieving effect of TENS is felt mainly in the area surrounded by the TENS electrodes.
How do I choose the right amount of channels?
First of all, think of your situation. Where do you feel pain in your body? How large is the painful area? Is your entire back painful or just a small part of your neck?
Let’s show an example of how to determine the right amount of channels:
Imagine, that your neck is painful in a palm-sized area. For this painful area, you can easily use a single-channel device, since the area between two electrodes can easily cover this.
Now imagine, that the painful area is larger, for example your entire knee. In this case, the treatment area provided by a one channel device is only large enough to cover one side. This would mean that with a one channel device you’d need to treat each side of your knee separately, or you would need a two channel device.
Taking the example further, imagine that both of your knees hurt. A two channel device could treat an entire knee at once, but not both at the same time. This means either a doubled treatment time, or the need for a 4 channel TENS unit.
The case is similar for other types of pains. The goal is to be able to treat your pain in as few steps as possible. If your back hurts from neck to waist, you can handle the entire area with a single channel device in only 4-5 steps. By the time you reach the waist, the pain-relieving effect on your neck is gone. A two-channel device requires 2-3 repetitions - on the neck, back and finally the lumbar area. With a four-channel device, you can manage the entire back area once.
In my opinion, it is no longer worth buying a single-channel device, because prices for two and especially four channel devices has fallen drastically. A dual channel device is recommended if the area to be treated touches less than two palms and one side.
However, the most future-proof purchase is a 4 channel TENS unit. While having 4 channels allows for treatment of large painful areas, it is not "mandatory" to use all channels on a 4-channel device always. If you have pain in a smaller area, you can use only 1 or 2 channels. However, if your entire back or your hips on both sides becomes painful, the 4-channel TENS unit will not be limited in how it can help you.
When I get my TENS unit, what programs should I use?
Generally, TENS units contain several different programs. The reason for this is that different types of pain and different body regions require a slightly altered impulses. The difference can be in the form of pulse, duration, frequency and intensity. These parameters are researched perfected by professionals. On the device, only the painful body part and treatment goal is what needs to be selected.
Basic level devices usually contain two types of programs. Constant high frequency (also called traditional) or constant low frequency (called endorphin) treatment. They are suitable for any type of pain and can be applied to almost any part of the body. However, due to the constant frequency, your body quickly gets accustomed to it. An initially strong pain-relief effect will decrease drastically after a few days of use.
You should choose a device that has a MODULATED TENS program, which is one of the most up-to-date developments in TENS technology. Modulated programs have been developed to prevent your body from getting used to the pain relieving effect. Modulated TENS treatments slightly change and vary the treatment parameters, so your body does not get used to it easily. This preserves the effectiveness of the treatment. Modulated TENS is essential for treating arthrosis, arthritis and rheumatism, etc. Without it, a device can only relieve these kind of pains for a few days!
Devices which support modulated TENS usually have the term in their descriptions. In my opinion, device that do not support this function are obsolete. We recommend to choose a modern and efficient device that provides modulated TENS, especially in case you suffer from chronic pain.