10/05/2026
It’s a long read but worth it. I see so many horses struggling and feel this could be the reason.
My mare was one of those and now so much happier and regulated.
🐴🫁 𝗪𝗵𝗮𝘁 𝗶𝗳 𝘆𝗼𝘂𝗿 “𝘀𝗽𝗼𝗼𝗸𝘆” 𝗵𝗼𝗿𝘀𝗲 𝗶𝘀𝗻’𝘁 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 𝗮𝗻𝘅𝗶𝗼𝘂𝘀 - 𝗯𝘂𝘁 𝗽𝗵𝘆𝘀𝗶𝗰𝗮𝗹𝗹𝘆 𝘂𝗻𝗮𝗯𝗹𝗲 𝘁𝗼 𝗲𝘅𝗵𝗮𝗹𝗲?
This is not always a training problem.
Sometimes, it is a body that cannot regulate itself.
Some horses never truly seem able to switch off.
They spook at shadows. Brace through the whole body. Rush every transition. Struggle to take a deep breath. Hold tension through the jaw, the sternum, the belly. React sharply to the leg. Fight softness in the contact.
And we label them:
Difficult. Anxious. Reactive. Naughty.
But what if the nervous system is responding to something physical - not behavioural?
🫁 𝗦𝘁𝗮𝗿𝘁 𝗵𝗲𝗿𝗲: 𝘁𝗵𝗲 𝗱𝗶𝗮𝗽𝗵𝗿𝗮𝗴𝗺 𝗶𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗮 𝗯𝗿𝗲𝗮𝘁𝗵𝗶𝗻𝗴 𝗺𝘂𝘀𝗰𝗹𝗲.
In the horse, the diaphragm is one of the primary pressure regulators of the entire body.
It attaches to:
▪️ the sternum ▪️ the caudal ribs ▪️ the thoracolumbar region via the crura ▪️ major fascial and visceral structures throughout the trunk
Every single breath ripples outward, influencing: ✔️ pressure through the thorax ✔️ venous and lymphatic return ✔️ rib mechanics and mobility ✔️ sternum rotation ✔️ thoracolumbar tension ✔️ pelvic stability
This means a horse that cannot breathe freely cannot move freely.
It is not just a training gap.
It may be a mechanical one.
𝗡𝗼𝘄 𝗮𝗱𝗱 𝘁𝗵𝗲 𝗹𝗮𝘆𝗲𝗿 𝗺𝗼𝘀𝘁 𝗽𝗲𝗼𝗽𝗹𝗲 𝗻𝗲𝘃𝗲𝗿 𝗰𝗼𝗻𝘀𝗶𝗱𝗲𝗿: 𝗴𝗮𝘀 𝗲𝘅𝗰𝗵𝗮𝗻𝗴𝗲.
Breathing is not only about bringing oxygen in.
It is equally about getting carbon dioxide out - efficiently, continuously, with every breath.
If a horse is stuck in a shallow breathing pattern, whether braced in inspiration or expiration, it may not be clearing CO₂ as efficiently as it should.
The body then has to work harder to maintain acid-base balance - its internal chemical stability.
One of the systems involved in this buffering process?
➡️ The kidneys.
The kidneys help regulate pH by adjusting bicarbonate and hydrogen ion balance, helping the body maintain the narrow blood pH range required for normal function.
This is not dramatic.
It happens quietly.
But over time, in a horse that is chronically restricted and chronically stressed?
The body starts compensating everywhere.
🫘 𝗕𝘂𝘁 𝘁𝗵𝗲 𝗸𝗶𝗱𝗻𝗲𝘆𝘀 𝗮𝗿𝗲𝗻’𝘁 𝗷𝘂𝘀𝘁 𝗰𝗵𝗲𝗺𝗶𝗰𝗮𝗹 𝗯𝘂𝗳𝗳𝗲𝗿𝘀.
They are physical ones too.
This is where it gets extraordinary and where most people never look.
The kidneys are retroperitoneal, meaning they sit behind the abdominal lining, tucked high under the last ribs.
With every deep, functional breath, the diaphragm moves caudally towards the tail.
That motion does not just move air.
It changes pressure. It moves fascia. It influences organ glide.
The diaphragm is not just breathing.
It is moving the internal body.
If the diaphragm is braced, this physical pumping action becomes reduced.
And in my osteopathic assessment, this can show up as: ▪️ lumbar sensitivity ▪️ abdominal guarding ▪️ reduced rib mobility ▪️ pelvic asymmetry ▪️ a horse that feels shorter in one stirrup ▪️ or a horse that struggles to soften through one side
⚡️ 𝗧𝗵𝗲 𝗮𝘂𝘁𝗼𝗻𝗼𝗺𝗶𝗰 𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝗼𝗻
There is another layer deeper still and this is where behaviour, biomechanics and the nervous system converge.
The vagus nerve passes through the diaphragm via the oesophageal hiatus.
The vagus nerve is part of the “rest, digest and regulate” system.
So when the diaphragm is chronically tight, restricted or braced, the horse’s ability to access relaxation may be affected too.
This is not “just anxiety.”
This is anatomy.
And it is one reason I am always careful about labelling horses as simply difficult, sharp, stressy or naughty.
𝗧𝗵𝗲 𝘃𝗶𝘀𝗰𝗲𝗿𝗮𝗹 𝗹𝗮𝘆𝗲𝗿 𝗺𝗮𝘁𝘁𝗲𝗿𝘀.
The left kidney has fascial and ligamentous relationships with the spleen.
The right kidney sits in close relationship with the liver.
So when the diaphragm is restricted, it does not only affect the lungs.
It can alter the glide, pressure and fascial relationships of the organs beneath it too.
And this is why one-sidedness is not always a schooling problem.
A horse that struggles on one rein, skips a lead, travels crookedly or feels blocked through one side may not simply need more repetition.
They may need the body to be able to organise itself internally first.
Because when you ask for softness, bend, lift, collection or a lead change…
you may be asking that horse to move through a physical blockage it cannot simply “try harder” through.
You are not fighting their mind.
You may be meeting their internal topography.
This is why some horses transform when we shift the conversation to: ✔️ rib mechanics and mobility ✔️ sternum rotation ✔️ diaphragm function and coordination ✔️ thoracic inlet restrictions ✔️ visceral tension - kidneys, spleen, liver ✔️ vagal tone and autonomic regulation ✔️ how pressure moves through the whole system ✔️ how the horse is actually organising itself internally
Not just:
Can this horse do the movement?
But:
Can this horse regulate itself well enough to even access relaxation?
The horse that looks naughty…
is sometimes the horse that is working incredibly hard just to stay functional inside a body that is struggling to regulate.
That is not a discipline problem.
That is not a respect problem.
That is not even primarily a training problem.
That is a body asking for help in the only language it has.
And the moment we start listening differently - the whole conversation changes. 🐴
💬 Have you ever had a horse that felt stuck in the ribs, struggled with one lead, or felt shorter in one stirrup no matter how much you worked on softness?
Drop your experience in the comments - I read every single one.
🛑 𝗦𝗧𝗢𝗣 𝗚𝗨𝗘𝗦𝗦𝗜𝗡𝗚. 𝗦𝗧𝗔𝗥𝗧 𝗔𝗦𝗦𝗘𝗦𝗦𝗜𝗡𝗚.
I have put together a Diaphragm & Rib Mobility Checklist - a step-by-step PDF guide to help you start recognising these physical patterns before they are dismissed as “behavioural” problems.
Want the checklist?
Join my email community and I’ll send the guide straight to your inbox. 📧🐴
Register your email here:
https://www.helenthornton.com/email-updates
It’s free - because horses deserve better than being labelled difficult.
Image: https://pferde-gesund-bewegen.de/das-zwerchfell-oder-auch-diaphragma-des-pferdes/
