Friday, 17 May 2013
TMJ a joint of great importance and influence
The early summer made a highly acclaimed entrance here in Norrbotten yesterday and we celebrated it with a Preschool day at Tallbackkottarna, where my two older boys have been and the youngest still are. All animals on the farm is enjoying the warmth; horses, cats and dog lounges in the sun. We are waiting for the "big green" to take place and according to the weater forecast it might be happening this very weekend.
The theme for today is the temporomandibular joint (TMJ). The TMJ is an important point in the body for both human
Looking at the head from a skeletal perspective, upper jaw and skull is one unity and the mandibular is a separate unity. Temporomandibular joint is the point in which the lower jaw moves relative to the rest of the head. The masseter muscles are so-called anti-gravity muscles, that holds the lower jaw in place. When we chew or talk, it is the lower jaw that moves up, down and sideways. Quite often I see tendencies in people that they lift their head up and away from the lower jaw when they open their mouth. The gesture becomes more evident in some singers who want to get their voice out with some force. Such a motion affects the balance of the body quite a lot because the head itself weighs several kilos (4-6 kg for an adult).
Since the jaw muscles are designed to keep the lower jaw up it is relaxed when the mouth is closed and in work when the mouth opens. This is true for both human and horse. The temporomandibular joint has the ability to move sideways, it is needed so we are able to grind the food with our molars (teeth at the back of the mouth). In horses, eating much larger amounts of rough fiber than we do, this grinding motion is important in getting the food properly micronized.
The concept of having a locked jaw is common in both man and horse, and for both of us a locked jaw causes the teeth to wear unevenly, we get bite problems, which in turn affects the temporomandibular joint, and that in turn affects the muscles around the TMJ and neck and muscular disorder moves further into the body. In humans, tensions in relation to TMJ is a common cause of migraine and we have expressions that connotes with how anger, anxiety and frustration manifests itself in and around the TMJ; having clenched jaws and grind teeth are two examples. By actively biting your your teeth together you can feel the tonus of the neck muscles change.
A poorly fitted bit and improperly thightened nosebands increases the risk of ulceration of the mucous membranes, puts pressure on the bars and tongue and pain causes tension in the TMJ in horses. These tensions locks the cervical spine and since the horse uses his neck as a balance bar, it is easy to perceive the horse as rigid and unbalanced. The horse should have a relaxed, closed mouth to have access to both breathing and a supple cervical spine. Closing the mouth with nosebands is to ignore the cause of, as it is often called, an anxious mouth. An anxiuos mouth is an indicator of an underlying cause that can be found in the horse or rider.
My horses got a check up of their mouths recently and it turned out that my mare had traces of bit related injuries in her mouth that will require careful fitting of a bit, if I ever consider to ride her bitted. The mucous membrane on the bars had slided up against her teeth. A bit like a rug would do when dog would slides it up coming at full speed. She had changes in the bone tissue in the bars themselves, which is almost a guarantee that she would experinece pain in the mouth having to have bit.
Everything is connected in both horse and human. We are basically designed to work, and with an open mind to our own and the horses' signals when something seems to have fallen out of balance and we sence that equilibrium is lost, we should give ourselves the time to investigate before the damage is a fact.
In September, a course in Applied Equine Podiatry (AEP) is held in Boden again. I heartily recommend this course to anyone who wants to learn how the horse foot (= all the tissue inside the hoof capsule) works and the stimulus it needs for the horse togrow a healthy hoof. Everything we do with our horses is a compromise with theiranimal naturel, so the better we become in our compromises the better our horses can stay in tune with their animal nature. Read more about the AEP and sign up via www.appliedequinepodiatry.org