This section is from the book "The Horse - Its Treatment In Health And Disease", by J. Wortley Axe. Also available from Amazon: The Horse. Its Treatment In Health And Disease.
This is a long triangular muscle situated at the upper border of the neck, where it commences at the second cervical vertebra and extends backward to the fifth dorsal vertebra.
Origin. - From the superior border of the ligamentum nucha? and the superior spinous processes of the 2nd, 3rd, 4th, and 5th dorsal vertebrae.
Insertion. - Into the inner surface of the cartilage on the upper border of the scapula.
Action. - To draw the scapula upwards and forwards. Acting when the scapula is fixed, it would incline the neck to one side.
 
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