“Does My TENS Unit Actually Help Me Recover From Painful Injuries and Problems?”

Great question! It’s a little to broad to give any definitive answer but the following post can help you understand TENS therapy and chronic pain much better. 

The answer is, it depends. Great answer, I know. 

Bear with me a moment while I try to explain a little of a complex situation in generalities.

First, it depends on what you mean by treat.

I’m assuming you mean that treatment with the TENS unit reduces future pain severity and/or frequency, even when it’s not being used.

The way most people use a TENS unit might temporarily help pain… or in some cases increase it. 

The TENS unit can help reduce future pain, depending on it’s use, the very specific problem, and the inididual using it. Your specifc problem or injury is important when considering how to reduce or eliminate your pain.

-For example if a specific pain generator continues to exist, then it’s likely that it might continue causing at least some ongoing pain generation… Having said that – the pain generator in many people might not be what they have been told is causing the pain, but that is beyond the scope of this discussion.

The TENS unit will ultimately fire different types and combinations of nerves depending to a large degree on the intensity of current used.

If the current is turned up causing significant sensation or even muscle contraction, then it will fire what are small ‘pain’ nerves in addition to the larger diameter nerves that carry other info. When we fire a nerve over time, it has a real probability to make it more likely to fire in the future… more on that in a minute.

We are wired in such a way that the larger nerve fibers have a probability of ‘turning off’ the smaller fiber nerves. 

The larger fibers will have a likelihood of firing with lower current than the smaller fibers.

If we fire the larger fibers and minimally fire the smaller ‘pain’ fibers then we might be able to create adaptive changes making it more likely these larger fibers turn off the smaller ‘pain’ nerves.

The problem here might be that the firing of the ‘pain’ nerve results in adaptive changes that make it more likely to fire. 

These adaptive changes are called ‘neuro-plasticity‘ – a big word that means the nervous system changes with activity. It basically re-wires itself to a certain degree.

The nervous system is similar to the muscular system in the way it adapts to stress, activation, etc.

Say you’re a guy that wanted to get bigger biceps for summer so that you could impress all the women at the beach or whatever.

You go to the gym and begin doing your biceps curls in the squat rack, upsetting all the hardcore bodybuilders but it’s for a good cause so you soldier on! 

If you do the right amount of weights, the right amount of sets, over the right amount of time (weeks/months), and allow the appropriate amount of time for recovery then you are likely to be well on your way to having the beach biceps that you’ve always dreamed of having. 🙂

These bulging biceps occur in a very similar way to what happens with neuro-plasticity.

If a nerve is fired at a certain frequency for a period of time repetitively while allow sufficient time for recovery, then it will begin to branch out, essentially getting bigger and stronger. 

This will make it more likely to fire. 

In some cases, this is a good change. 

In other cases, it can be a very bad change for the person.

This is what happens with chronic pain. 

The repetitive firing of the pain system is causing neuro-plastic changes making it more likely to fire with a smaller stimulus. It’s an unfavorable change for the person because the pain system is much more likely to be active. 

Returning to our little Romeo looking for love example…

If he uses too heavy much weight, then he will probably get injured, but more importantly for this example – he will not grow enviable Arnold-like bicep peaks and will not be beach ready for the summer.

The same thing would happen if Romeo decided to blast his biceps every day in the gym to speed up the process. He would very likely exceed his recovery abilities and again will be forced to wear shirts on the beach thereby reducing his opportunities for finding the love of his life.

It’s sad, but true.

Anyway, getting back to the pain and chronic pain discussion. 

We want to direct the changes in the nervous system, the neuro-plasticity, in a way that will benefit and not be neutral or even harm the person.

If treatment with a TENS unit or anything else results in increased activity in the pain system over time (the equivalent of building bigger pain biceps), then it’s likely to cause more pain over time.If the treatment increases plasticity in the nervous system that ‘turns off’ the ‘pain’ nerves then it is likely to help the chronic pain sufferer feel less pain.

As it turns out the larger fibers that turn off the pain nerves are in rich abundance in muscles, tendons, and joints. This is one of the reasons that Chiropractic manipulation and other movement based treatments can help so many chronic (and acute) pain sufferers.

Beyond the scope of this long article, but relevant to the understanding of treating chronic pain – other higher levels of the nervous system are very important in whether you feel pain or do not feel pain.

We do need to understand that when the nerve fires, it sends the message up the nervous system. It doesn’t just disappear. It has the probability of effecting neuro-plastic changes all the way up to the highest areas of our brains.

We can look at the spinal cord all the way up to the cortex.

All of these parts can be activated, they can be changed in a good way or a bad way to change pain and it’s likelihood of continuing to occur. 

This is why the treatment of chronic pain is challenging… by the way, treatment of any pain regardless of cause can be successful to varying degrees just by applying this information whether it’s a headache, migraine, neck pain, back pain, pain in an extremity, or anything else.  

There are many, many factors that must be considered… and the treating doctor must either understand what I’ve mentioned (and more) or just get lucky to treat the pain / chronic pain patient with the greatest chance of success.