Readers of the blog know that the psoas is my favorite muscle; my favorite bone is the hyoid. Of the 206 bones in the body, 205 of them influence the movement of at least one other bone. The hyoid bone is the only free floating bone in the whole body which means it is connected via ligaments and muscles but it doesn’t articulate with any other bone.
Some anatomy geeks might make the claim that the kneecap is a floating bone but the kneecap is really part of the quadriceps muscle and interacts with the femur bone disqualifying it from the floating distinction. The kneecap is a sesamoid bone, a type of bone that is embedded into tendons. The presence of a bone within a tendon increases the mechanical efficiency of the muscle connected to that tendon. But the hyoid is a bone like no other.
The hyoid is the only bone of the throat— which houses the larynx, pharynx, and esophagus. In the context of evolution the hyoid is directly related to the development of speech. There are variations of the hyoid in other animals but its unique placement in our upright posture allows it to work with the larynx and tongue to help us speak. No other animal has a larynx low enough to produce sounds and language like the human animal.
The hyoid bone is located above the thyroid cartilage and in front of the 3rd cervical vertebrae of the neck connected by a network of muscles and ligaments that sustain the hyoid bone beneath the tongue. There are nine muscles that connect the hyoid bone to the upper body. Six of these muscles are above the hyoid and three are below.
In addition to facilitating our ability to speak with the larynx and tongue the hyoid functions to support the weight of the tongue. The muscles above the hyoid are the muscles of deglutition—swallowing. These muscles form the floor of the mouth and aid in certain phases of swallowing.
These are the literal functions of the hyoid and in the next post I will cover how the awareness and understanding of hyoid can help us to change and improve our movement patterns.
But first a final factoid; I take my learning anywhere I can get it, and I learned via Law and Order—the most ubiquitous show in the history of television—that as a general rule if a hyoid bone is fractured when someone suffocates, the death will be a considered a homicide. As an aside, my wife watched so much Law and Order during her pregnancy with our daughter that I thought the sounds of the prison bars slamming shut would be a sense memory of hers for life.