Musculus semispinalis capitis
The semispinalis capitis is a massive muscle forming the bulk of the dorsal neck. It is divided into the complexus (dorsal part) and biventer cervicis (ventral part). It originates from the transverse and articular processes of the upper thoracic and all cervical vertebrae and inserts on the nuchal crest and occipital protuberance of the skull. Its actions are to extend the head and upper neck, act as the primary head elevator, and resist gravity pulling the head down. It is innervated by dorsal branches of cervical spinal nerves (roughly C1-C6). It is what creates the topline of the neck.
Origin: Transverse and articular processes of the upper thoracic and all cervical vertebrae
Insertion: Nuchal crest and occipital protuberance of the skull
Action: Extends the head and upper neck; primary head elevator; resists gravity pulling the head down
Innervation: Dorsal branches of cervical spinal nerves (C1-C6)
Atrophy or dysfunction can contribute to poor head carriage or reduced neck strength. Relevant in evaluations of neck function, after trauma, or in cases of cervical nerve dysfunction. It is important for maintaining head elevation.
## Overview Poor topline or ewe neck is underdevelopment or atrophy of the muscles along the top of the neck, creating a concave upper profile and prominent lower neck. The horse struggles to achieve
## Overview Neck crest dropping, or fallen crest, occurs when the heavy fatty crest of an obese horse or one with equine metabolic syndrome overwhelms the supporting muscles and ligaments and falls p
Loss of topline or difficulty elevating the head after illness or trauma should be evaluated. Balanced work and correct head carriage help maintain neck strength.
## Overview Poor topline or ewe neck is underdevelopment or atrophy of the muscles along the top of the neck, creating a concave upper profile and prominent lower neck. The horse struggles to achieve a round frame and tends to go inverted (head up, back hollow). It is both a cosmetic and functional concern. ## Causes Lack of correct conditioning, conformational predisposition, or chronic pain leading to disuse. ## Diagnosis Visual assessment of neck conformation and muscle development. ## Treatment Targeted conditioning that encourages long-and-low work and correct engagement. Address any underlying pain. ## Recovery and Prognosis Improves with consistent correct work, though conformational limits exist. ## Prevention Proper training that develops the topline. Signs include: concave dorsal neck profile; prominent ventral neck; difficulty achieving a round frame; inverted posture under saddle
## Overview Neck crest dropping, or fallen crest, occurs when the heavy fatty crest of an obese horse or one with equine metabolic syndrome overwhelms the supporting muscles and ligaments and falls permanently to one side. It is a cosmetic issue and a marker of insulin dysregulation and laminitis risk. Once fallen, the crest does not return to midline. ## Causes Excessive nuchal fat deposition associated with obesity or equine metabolic syndrome. ## Diagnosis Visual appearance of a crest that has flopped to one side, plus assessment for metabolic disease. ## Treatment Weight loss and management of insulin dysregulation. The fallen position itself cannot be corrected. ## Recovery and Prognosis The crest remains fallen. Metabolic control reduces further risk of laminitis. ## Prevention Maintain appropriate body condition and manage equine metabolic syndrome early. Signs include: fatty crest falls to one side; irreversible; associated with insulin resistance and laminitis risk
Atrophy or dysfunction can contribute to poor head carriage or reduced neck strength. Relevant in evaluations of neck function, after trauma, or in cases of cervical nerve dysfunction. It is important for maintaining head elevation.
Loss of topline or difficulty elevating the head after illness or trauma should be evaluated. Balanced work and correct head carriage help maintain neck strength.
See the Semispinalis Capitis on our interactive 3D horse model. Open 3D Model