Interspinalis Thoracis (Musculus interspinalis thoracis)
Educational content only — not medical advice.
Anatomy
Short, deep, paired muscular slips connecting adjacent spinous processes within the thoracic spine, primarily present in variable fashion between the first and second, and tenth through twelfth thoracic vertebrae. Although rudimentary in the mid-thorax due to restricted extension, they contain an exceptionally high density of muscle spindles that act as critical proprioceptive sensors monitoring vertebral displacement and guiding postural reflexes.
Origin & insertion
From the apex of the spinous process of one thoracic vertebra, into the spinous process of the vertebra above.
Action
Aids in extending adjacent thoracic vertebrae; provides essential postural proprioception.
Innervation
Posterior rami of thoracic spinal nerves.
Clinical notes
Though tiny, high spindle density makes interspinal muscles key drivers of reflex paraspinal hypertonicity and segmental somatic dysfunction following thoracic spinal sprain.
Related structures
Educational references
FAQ
What is the role of the Interspinalis Thoracis?
Short, deep, paired muscular slips connecting adjacent spinous processes within the thoracic spine, primarily present in variable fashion between the first and second, and tenth through twelfth thoracic vertebrae. Although rudimentary in the mid-thorax due to restricted extension, they contain an exceptionally high density of muscle spindles that act as critical proprioceptive sensors monitoring vertebral displacement and guiding postural reflexes.
Why is the Interspinalis Thoracis clinically important?
Though tiny, high spindle density makes interspinal muscles key drivers of reflex paraspinal hypertonicity and segmental somatic dysfunction following thoracic spinal sprain.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details