How does a TENS unit help to relieve pain? Backaches can be excruciatingly painful and debilitating to the point of leaving someone almost unable to move. When back pain sets in, it’s almost impossible to think of anything else besides getting relief. Although electric currents are probably the last thing most of us want near our bodies, especially if in pain, it turns out electricity may be just what our backs need when injured. The exact method of delivery is known as transcutaneous electrical nerve stimulation. Continue reading to find out why it might be the solution so many of us need when our backs are out of whack.
A Brief History of Using Electricity for Back Pain
Believe it or not, using electricity to treat pain goes back as far as 2500 BC. Stone carvings have been found from that period that show a species of catfish that has organs that produce electrical impulses. The stone carvings depict people making use of this electrical impulse to help alleviate their pain. The court physician to Claudius, Scribonius Largus, was known to be very fond of using electric fish for this and other purposes. Using electricity for these reasons wouldn’t be seen again until the 16th century. Fortunately, the methods employed back then did not survive. However, we do have these early beginning to thank for what we now know as TENS.
How Transcutaneous Electrical Nerve Stimulation Works
TENS operates on what is known as the gate-control theory. This theory, which was first posited in 1965, states that pain occurs because of movement in small nerve fibers. By stimulating larger nerve fibers, the theory goes, you can actually reduce a patient’s perception of pain in that area.
The “gate” in its name refers to is a hypothetical one that the theory proposes as well. It is helpful to think of this supposed gate existing within the dorsal horn of the body’s spinal cord. When the gate is opened, messages can be sent to the brain to alert it that there is pain coming from small nerve fibers in the back. However, if this gate is made to shut, the brain is never made aware of the pain and, thus, the patient never feels it.
A TENS machine accomplishes this through nonintrusive means. The machine itself generates electricity which is transferred to the patient’s body through electrodes which are placed on the skin. Generally, they are placed directly on the source of pain or near the area where it is stemming from.
It’s still up for debate how electrodes should be placed in order to best relieve pain. More than likely, the exact locations that work best for some patients may not be best for others, pointing to a treatment that needs to be customized for each patient.
The actual frequency at which the electrical current is delivered has also proven to affect the kind of relief experienced. High frequency current has been shown to actually reduced the amount of pain expressed by the smaller fibers mentioned earlier. On the other hand, lower frequency electrical current has shown capable of forcing the body to produce and release endorphins, which leads to an overall feeling of pain relief. TENS can also be programmed to combine the two frequencies so that a patient experiences less pain in the first place and more endorphins to deal with what is felt.
How Long Transcutaneous Electrical Nerve Stimulation Lasts For
While TENS can help relieve pain, there is still some debate over how long it lasts for. Some patients report that their pain returns as soon as the TENS therapy is complete. However, others have been able to carry on without pain for more than a day.
The conventional form of TENS, which is a high frequency current, triggers pain relief quickly, but many report that its effects disappear equally fast when the machine is shut off. It’s for this reason that many back pain specialists, like chiropractors, simply use a TENS machine to ease the patient out of their current state of pain before adjusting their spine.
When a TENS machine administers low frequency electronic currents, the effects appear to be just the opposite. Pain relief takes much longer to set in; however, the positive effects also last much longer. It is with the low frequency variety that people have reported relief for more than a day.
Again, at this time, no one can explain the discrepancy between the amounts of pain relief some patients feel compared to others. Due to the often unbearable pain one can feel from a back problem, it seems unlikely that the placebo effect could be to blame.
One theory is that the varying amounts of endogenous opioids in each patient’s body may play a role on their reported amount of relief. It is also possible that habituation occurs in those who experience TENS therapy on a regular basis and thus that they begin reporting lower amounts of relief.
The Machine Itself
As mentioned earlier, one of the benefits of using a TENS machine is that it’s non-intrusive. The machines are often made to be portable, meaning the electricity is produced via a battery. However, other systems are simply plugged into a wall.
There are usually four electrodes used, though it’s not uncommon to see two or even one large one that’s meant to span the width of the lower back.
Frequencies generally range from around 10 Hz to over 50 Hz. This range of frequency allows TENS machines to either operate below the intensity of motor contraction or at a frequency that can actually induce it.
TENS units are often used by general practitioners, chiropractors and even masseuses. It doesn’t take any special license to operate them and home units are even available for people who wish to self-administer. However, given the sensitive nature of back pain and the potential to do further damage, it’s recommended that patients seek the counsel of a physician before using them on their own.
If you suffer from back pain, you already know how unbearable the sensation can be. Fortunately, transcutaneous electrical nerve stimulation has shown a lot of promise in bringing about relief. While we still have a lot to learn about the machine and its effects, countless patients already swear by it.