The Hyoid Apparatus


“Every muscle in the horses body eventually connects to the hyoid bone”


The hyoid apparatus is made up of several paired bones and is located in the lower jaw area. 


It has attachments to the tongue, the poll and the temporomandibular joint (TMJ). Its main function is to support the tongue and it helps with swallowing, breathing, hearing, balance, steering and making noises. The fascial network that attaches it to the cervical (neck) spine helps maintain the position of the head.  

There are quite a few muscles that act on the hyoid, some are quite big like the omohyoid muscle that attaches near to the shoulder joint. This means any dysfunction of the hyoid apparatus can cause front limb issues which can eventually escalate to issues with the hindquarters and back. 


When looking at how the horse moves from a muscular point of view, we see how muscles are connected and maybe dysfunctional via fascial lines. Fascia is a web of connective tissue surrounding our muscles, tendons, bones and organs. It connects the muscles together and allows them to communicate. This means that a restriction in one part of the fascia will cause dysfunction throughout the fascial line. Even a scar on the hind end can have an affect on the poll area as it restricts the fascial chain.  

It is really common that horses that are sore in the poll area will show pain through the back and the hind end. In a lot of cases once the poll is released the hind end will also be released. 


As the hyoid is attached to the tongue, larynx and the neck vertebrae, anything that creates tension in the lower jaw (ill fitting bit, riding with too much flexion, tight noseband) will affect the horses breathing and cause stress while being ridden. A saddle that interferes with the movement of the shoulder can also affect the hyoid through the omohyoid muscle. 


Unlike humans the hyoid apparatus connects to the temporal bones, giving it a link to the temporomandibular joint (TMJ) which is a site of tension in horses.


Making sure the teeth are well balanced and keeping the cheek piece buckles away from the TMJ can help relieve pressure here. 

Symptoms of a dodgy hyoid 

How to check for imbalance?


To find the hyoid, run your hand down from the top of the horse's throat toward the nose. You’ll feel a hard lump suspended in the tissue just before the jaw narrows, this is the hyoid. To feel for restrictions apply pressure to the left and right of the hyoid and see how the horse reacts. 


So how is it released?


A combination of cold laser and mobilising the tissues surrounding the hyoid can be used. Treating the horse as a whole along the fascial lines will help restore functionality.