11/10/2019
The two long muscles that run along a horse’s back on either side of the spine are called the longissimus dorsi muscles. These, along with the long abdominal muscles, are the most powerful locomotor muscles in the horse’s body (aka muscles of movement), but they can only function when they are free to alternately contract (shorten) and de-contract (lengthen).
In his book Tug of War, Classical Versus “Modern” Dressage, German rider and equine veterinarian Dr. Gerd Heuschmann, describes the function of the back:
• When the horse’s head and neck are forward and downward, as in grazing, the relationship between the nuchal ligament and the supraspinous ligament serves to raise the back, releasing the longissimus muscle and allowing it to “swing.”
• When the horse’s head and neck are positioned too high, it tries to support the rider by tensing its longissimus muscle, resulting in a “hollow” back, resistance, poor gaits (due to the abdominal muscles being unable to draw the hind limbs under the body), and lameness. (Heuschmann 52)
Thanks to the work of Eleanor Criswell Hanna Ed.D of the Novato Institute for Somatic Research and Training (the creator of Equine Hanna Somatics®), we also know that a horse who is unconsciously maintaining chronic tension in the longissimus dorsi and other muscles that contribute to a high head, short neck, dropped back and trailing hind limbs is expressing an Habitual Posture influenced by the Green Light reflex.
A horse who is stuck in the Green Light Posture has all of the same effects on the functional anatomy of the horse’s hollow back as described above by Dr. Heuschmann - whether or not it is under saddle.
And helping a horse get free of a Posture influenced by the Green Light Reflex is exactly what we do in !!!
