The musculi interspinales are part of the intrinsic back muscles.
Anatomy
The musculi interspinales are arranged segmentally and are present in the cervical and lumbar regions of the spine. They are absent in the thoracic region, except between the 1st and 2nd, 2nd and 3rd, and 11th and 12th thoracic vertebrae, and between the 12th thoracic vertebra and the 1st lumbar vertebra. They connect the adjacent Spinous processes. There are 6 musculi interspinales cervicis, 4 musculi interspinales thoracis, and 5 musculi interspinales lumborum on each side[^1].
Innervation
The musculi interspinales are innervated by the dorsal rami (C1-Th3 and Th11 to L5)[^1].