Exercising neurodynamically

Neurodynamic stretching is a technical type of stretching, a loose collection of experimental stretching and positioning treatments for neuropathy based on the idea that “unhappy” nerve tissue can be cheered up. Although a bit obscure, it’s an interesting idea that’s been around for a long time. Variations on the theme have produce severeal other names: neural mobilization and neurodynamics, neural gliding or sliding or tensioning or — the most fun — neural flossing.

I wrote a review of neurodynamics back in 2021, and reader Brenden T. pointed out that I’d missed a key point about why one would try to stretch nerves: it’s not so much about “freeing” nerves from “adhesions” (which might not exist anyway) and more sensibly just about the value of stimulation. Motion is lotion.

I agreed. This post is my belated clarification.

Story time: self-serve neurodynamic stretching to the rescue?

Posts that kick off with happy anecdotes get 78.2% better engagement. Source? 20 years publishing experience in this business, common sense, and knowledge of human nature. We like stories a lot, even though we all know we’re not supposed to take them too seriously. So here’s a wee yarn about a reader’s success treating sciatica by, quite possibly, pulling her sciatic nerve free from the wall of its sheath. As you do.

After years of minor chronic back pain, she had a rapid escalation into full-blown sciatica over the course of a couple days. Her “instinct” was to stretch — maybe wise, maybe lucky. Experimenting rather freely, she deliberately tried to stretch in the way that most clearly exacerbated her symptoms — which takes some guts, and obviously isn’t necessarily safe, and the kind of thing I wouldn’t dare to actually recommend. Several minutes into her experimentation, she experienced a painful surge … and then complete and lasting relief.

“The impression of a ripping sensation was so vivid that I felt like I almost heard it, even though it probably wasn’t audible. The pain was 90% gone instantly. All the throbbing leg pain that had been driving me nuts and keeping me awake for 2 days was just gone. There was still a little deep burn left, but I think it was like how the site of a bad sliver is still tender after the sliver is out. I slept fine, and by the next morning it there simply wasn’t any pain left.”

That might be a story about actually physically freeing a nerve. But we can only speculate, and if such things happen at all, it’s probably quite rare.

Check out this 143-year-old example of another story like this…

Why indeed would one want to “drag at" an inflamed nerve? In 1880, Dr. Bramwell reckoned it was to break up adhesions. And he might have been right. But it also might be simpler than that. (Hat tip to Tom Jesson for this old citation.)

A humbler goal: maybe it’s just nerve exercise?

Those stories support the adhesion-busting idea … but that’s more or less the only support it’s got. And although neural gliding often does have the goal of breaking adhesions between nerves and their sheathes, not everyone thinks that’s the point. There is another reason to mobilize, stretch, tension, slide, glide, or floss nerves…

Rather than breaking icky sticky nasty adhesions, maybe the main point of neural tensioning is just to pull on nerves without optimizing for “glide” of the nerve within its sheath to break adhesions. It’s just a way of generally stimulating/exercising nerves, which is in turn is widely regarded a Good Thing.

And maybe it is, and maybe it’s good enough, and that's all that some professionals ever intended. Not everyone agrees that the purpose of neurodynamic stretching is to rip free nerves from possibly imaginary adhesions or entrapments.

Everything in physiology seems to thrive on just-right levels of stimulation. “Motion is lotion” and “exercise is the closest thing we have to a miracle cure” and so on. Tissue stagnancy might drive dysfunction and neuropathy — essentially an exaggeration of feeling increasingly uncomfortable if we are too still for too long.

Do nerves need their own exercise?

This justification for nerve stretching is probably on firmer ground than “it’s the entrapment, stupid,” but it’s still far from a slam dunk. I don’t think anyone doubts that physical stimulation is good for nerves in some sense, but … do we have to specifically stretch nerves to achieve it? Is it clinically important to do so?

It could be. Not everything in biology functions or heals well solely with the stimulation of normal activity! A simple example: deliberately washing wounds is dramatically better at preventing infection than just letting nature take its course. Simple mechanical flushing can be extremely powerful.

On the other hand, many medical interventions and “crutches” that supposedly facilitate healing have turned out to be surprisingly useless or even harmful. What actually assists the body is rarely obvious.

Science to the rescue? As usual, not so much

Rigorous study is the only way we’re ever really going to know if specifically stretching nerves is truly helpful — as opposed to, say, something else specific like stretching blood vessels, or something general like just doing some calisthenics.

So, do we have that? Hardly! A 2022 paper reviewed just eight studies of neural mobilization for back pain (see Peacock), and six had results in the “technically positive” category, but definitely nothing impressive. This is good fuel for wishful thinking for now, and that’s about it.

This is just a little excerpt. Read the full review here: