Some tension doesn't go away with stretching. A pull behind the leg that comes back every morning, tingling in the hand that comes and goes, a discomfort you can't put your finger on. Sometimes it isn't the muscle complaining. It's the nerve, and the tissue it has to move through.
This article expands Chapter 4 of the series I make with Gemma Castellano, fasciotherapist and osteopath. The carousel gave the idea. Here's the why: how nerves move, what happens when they can't, what the evidence says about neural mobilisation, and how to do the three exercises well.
1. Your nerves move (and they need to)
We tend to picture nerves as fixed cables. They aren't. Every time you bend your elbow, turn your neck or bend down to tie your shoes, your nerves lengthen, shorten and slide relative to everything around them.
One example: the median nerve, which reaches the hand through the carpal tunnel, shifts several millimetres at the wrist when you move your arm and hand. This has been measured with ultrasound. When you fold forward with straight legs, the sciatic nerve has to accommodate that whole journey from the spine to the foot.
A nerve is also connective tissue
A nerve isn't just nerve fibres. It's wrapped in layers of connective tissue, just like a muscle:
Endoneurium: surrounds each fibre.
Perineurium: bundles the fibres into fascicles.
Epineurium: wraps the whole nerve.
Mesoneurium: the loose outer layer that lets the nerve glide against muscles, bones and fascia.
In other words, the nerve lives inside the fascial system and is partly made of it. That's what the carousel meant by fascia being "the tissue where your nerves live".
Why moving matters so much to a nerve
Nerves need a constant blood supply, and they're sensitive to pressure and stretch. In classic animal studies, stretching a nerve by about 8% already reduced its blood flow, and around 15% almost cut it off (Lundborg & Rydevik, 1973). So the body prefers to share movement out: a bit of gliding here, a bit of lengthening there, and no single point taking all of it.
2. When the surroundings won't let it glide
If the layers around a nerve lose some of their ability to slide, the nerve has to stretch more for the same movement. It doesn't need to be damaged or "trapped". It's simply working with less margin.
What does it mean for fascia to "densify"?
Between the layers of fascia there's a lubricant, hyaluronan, that lets them slide over each other. Carla Stecco's research group proposes that with too little movement, overload or inflammation, it becomes more viscous and the layers glide less well. They call this densification. It's a hypothesis with solid anatomical grounding, though how to measure it in living people is still being worked out.
The carousel named three causes: stress, a sedentary lifestyle and overload. All three make sense. Moving little reduces gliding, overload irritates tissue, and stress raises background muscle tone and the sensitivity of the nervous system.
A nerve with little room becomes sensitive
This is the key point. A nerve working with little room doesn't necessarily hurt because it's compressed. What usually happens is that it becomes more sensitive to movement: the nervous system starts protecting that area.
That's why the symptoms are so hard to describe:
Tightness that doesn't improve with stretching, or gets worse.
Tingling that comes and goes.
Vague pain you can't pinpoint.
Discomfort that changes with the position of your neck, back or foot, even when the symptom is far away.
That last one is the most useful clue. If the tightness behind your thigh increases when you drop your chin, it's probably not only the hamstring. It's the nervous system, which runs from head to foot.
3. Neural mobilisation: accompany, don't force
Neural mobilisation (also called nerve gliding or neurodynamics) means moving the body in combinations that let a nerve glide through its path. The aim isn't to stretch the nerve. It's to restore the easy, pain-free movement it should have, and to calm its sensitivity.
That's what the carousel meant by "we don't force, we accompany".
Sliders and tensioners
There are two families of technique, and the difference matters:
Does it work?
The honest answer: it helps some problems more than others.
A 2017 systematic review (Basson and colleagues) found evidence that neural mobilisation reduces pain and disability in low back pain with leg symptoms and neck pain with arm symptoms.
For carpal tunnel syndrome, the results were mixed and less convincing.
Why might it help? Probably through several routes at once. The nervous system becomes less protective once movement feels safe again. And a cadaver study by Brown and colleagues (2011) found that gentle repeated movement spread fluid within the nerve, which could ease swelling inside it. The common thread is gentle and repeated, not big and held.
4. Honest nuances, and when to see someone
Fascia isn't always the answer. Tingling, numbness and diffuse pain have many possible causes: an irritated disc, carpal tunnel, diabetes, low vitamin B12, thyroid problems, and more. Fascia and nerve gliding are one piece of the picture, and a useful one, but not the explanation for every symptom.
Breathing calms more than it hydrates. The carousel says breathing hydrates fascia. There's no good evidence for that. What we can say is that slow, calm breathing lowers the stress response and muscle tone, and that changes how sensitive your nervous system feels. That's a strong enough reason to breathe well.
"Releasing" works through the nervous system. Manual therapy likely doesn't physically stretch or unglue tissue: the forces needed are far beyond what hands apply. It works by changing tone, sensitivity and how safe movement feels, which is exactly what a sensitive nerve needs.
See a doctor or physiotherapist if you have:
Numbness that doesn't go away, or keeps spreading.
Weakness: dropping things, tripping, a foot that slaps the floor.
Symptoms in both legs or both arms.
Pain that wakes you at night or follows a fall or accident.
Fever or unexplained weight loss along with the pain.
Go to an emergency service straight away if you notice numbness between your legs or around your bottom, or changes in bladder or bowel control.
5. Pilates + fasciotherapy
What Pilates brings
Pilates already works with many of the principles of neural mobilisation, often without naming them.
Axial elongation. Lengthening through the spine changes the space and load around the nerve roots and lets the system move from a more organised position.
Controlled, never forced, movement. Neural mobilisation works by repetition within a comfortable range. That's how Pilates is meant to be done.
Movement of the whole chain. Many exercises already combine spine, hips and limbs in the same positions nerve glides use. Spine Stretch Forward, Saw and Footwork with changing head positions are all relatives of the nerve slider.
Breathing. Slow breathing lowers the background tension that makes a nerve more sensitive.
In class, if someone feels tingling or a sharp pull in a stretch, we don't push through it. We change the position of the head, the ankle or the wrist, so the nerve gets more room and the exercise stays useful.
What Gemma brings
Gemma works hands-on. Her fasciotherapy looks for areas where the tissue doesn't glide well and the nerve has lost its freedom, and uses precise manual work to change how that area behaves and feels. Sometimes that opens a range that movement alone couldn't reach.
Together, the logic is simple: manual work creates a new option, and movement teaches the body to keep it.
