28/10/2026
A great post on the thoracic sling 🤩 something you all know I will concentrate alot of work on and talk about during treatments!
The thoracic sling is a shock absorber -
I feel like we've seen this bit everywhere now, but horses don't have a collarbone. Instead they have a joint comprised of soft tissue forming what’s known as a synsarcosis. The primary muscles involved in this are:
- Serratus ventralis muscles
- Pectoral muscles
- Subclavian muscles
When a horse has a healthy thoracic sling, they can not only elevate the ribcage between their shoulders, but they can also lower their ribcage between the shoulders.
This is something that we frequently overlook in traditional training; we idolise a horse’s capacity to lift through their back to support the weight of a rider, but we often don’t see the value in them being able to lower and/or rotate their ribcage between their shoulders.
This is perhaps because a lot of horses are biased towards being dropped through their thoracic sling - so it has becomed somewhat demonised.
Being able to drop through the thoracic sling is advantageous in situations when the horse needs to turn and run quickly. For example, in a feral setting when they cross paths with a predator, being able to lower their forehand and rotate through their ribcage enables them to turn and make a quick getaway.
In my opinion being able to access the entirety of their range of motion in the thoracic sling is essential for healthy shock absorption through the forehand.
It is often thought that shock absorption occurs only in the horse’s hoof, with their digital cushion and collateral cartilage supporting the force transfer from the ground through the distal (lower) limb and up to the body.
However I also think that shock absorption occurs through the synsarcotic nature of the thoracic sling; meaning there are multiple avenues for range of motion.
For example, with healthy thoracic sling development a horse can lower, elevate and rotate their ribcage between their shoulders in response to the biomechanical need.
This gives them lots of options for force transference through the body and I think that this is a protective mechanism for the following:
1) Supporting the health of the horse’s hooves by taking sole responsibility of shock absorption away from the digital cushion.
2) Supporting shock absorption through the leg by transferring the forces up into the muscles rather than being absorbed through the joint surfaces, tendons and ligaments of the distal limb.
3) Creating a protective mechanism for the base of the horse’s neck – to prevent compression associated with the brachial plexus – the bundle of nerves originating from the regions C6/C7/T1/T2 - and to enable the horse full cervical range of motion which in turn supports the health of the joint surfaces of the cervical spine.
Anecdotally, I often see a reciprocal system between hoof pain/pathology, lack of thoracic sling development and neck pain/pathology - and we have to address all of it to help the horse to truly find comfort.
Horses naturally carry more weight on their forehand, and then we increase that weight by adding a rider, and then we increase performance expectations by asking them to do complicated and unnatural movements for sustained periods of time.
I believe that all ridden horses – irrespective of breed or discipline - should have appropriate thoracic sling strength and range of motion as insurance to support the areas mentioned above. This is most commonly done through training, however I think different management practices are very important for setting training foundations.
📸 An example of a horse who is conformationally wither high (top photo) but whose topline and wither/croup relationship look totally different with thoracic sling activation (bottom photo).
Just think about how his movement pattern might differ from one photo to the next.
(Yes these pictures were taken on different days - please take them in the train your eye capacity intended.)
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