Rotatores Muscles

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction[edit | edit source]

Rotatores: deepest muscles in the transversospinalis group

The rotatores are the deepest muscles in the transversospinalis group, the deep layer of the intrinsic back muscles. These muscles lie between the transverse and spinous processes and are grouped by length of the fascicles, as well as region covered. The groups are rotatores, multifidus, and semispinalis.

Span the whole length of the vertebral column, being most developed in the thoracic region. It consists of 2 part long and short rotatores.

The Rotatores are:

  • The deepest muscles in the transversospinalis group and have the shortest fascicles, spanning one (short rotatores) to two segments (long rotatores).[1]
  • Part of the deep, core muscle groups of the body which assist in powering all limb movement, having a role as dynamic stabilisers[2].
  • Proprioceptive role, as they are highly rich in muscle spindles, sensing the positioning of each spinal motion[3].

Anatomy[edit | edit source]

Location and relations of the rotatores muscles

The rotatores can be divided regionally into: rotatores colli/cervicis; rotatores thoracis; and rotatores lumborum. Rotatores colli and lumborum are often inconsistent, and can be replaced by deep fibers of the multifidus. As rotatores thoracis are the most developed they are the usually described region.[4]

Rotatores thoracis muscle

  • Eleven pairs of small quadrilateral muscles, each segment containing a rotator brevis and rotator longus
  • First pair is between T1 and T2, and the last is between T11 and T12. The first or last pair can sometimes be absent.

Rotator brevis muscle

  • Origin: the upper, posterior part of the inferior transverse process
  • Insertion: lower border and lateral surface of the superior lamina

Rotator longus muscle

  • Origin: inferior transverse process
  • Insertion: base of the superior spinous process two levels above

Innervation: Rotatores are supplied by medial branches of dorsal rami of associated spinal nerves[1]

Action[edit | edit source]

Back Proprioceptors in action

Rotatores muscles are identified as thoracic rotators and back extensors in many texts but this action has not been often disputed examples below:

  • The rotatores are more likely stabilizers of the spinal column. These muscles occupy positions of very poor mechanical leverage and studies have shown a minimal contribution of the rotatores towards spine movements. Instead functioning as important stabilizers of the vertebral column, acting as extensible ligaments that adjust their length to support adjacent vertebrae[4].
  • Bogduk and McGill1 hypothesized that the rotatores and intertransversarii muscles predominate role is as proprioceptors not as mechanical stabilizers, as they are highly rich in muscle spindles. Rotators brevis spindle percentage volumes ranged from 4.58 to 7.30 times higher than those of multifidus and semispinalis[5]. Muscle spindles are the proprioceptors of muscle and are stimulated by stretch. They are likely affected during active and passive end-range rotational movements, eg baseball swing, a golf swing, passive stretch, or an end-range lumbar rotational mobilization technique[3]

Physiotherapy[edit | edit source]

Low back pain is a common and costly complaint

Impaired proprioception resulting from injury may degrade lumbar motor function, increasing risk of reinjury. Restoring proprioception of the lumbar spine after injury should be a goal of treatment. This involves restoring the deep core muscles of the spine[6].

References[edit | edit source]

  1. 1.0 1.1 Radiopedia Transversospinalis Available: https://radiopaedia.org/articles/transversospinalis-muscle-group?lang=us(accessed 30.1.2022)
  2. New Heights Achieving core strength. Available: https://newheightschiro.com/news/achieving-core-strength-the-correct-way/(accessed 30.1.2022)
  3. 3.0 3.1 Musculoskeletal Key The Anatomy and Pathophysiology of the CORE Available: https://musculoskeletalkey.com/the-anatomy-and-pathophysiology-of-the-core/(accessed 30.1.2022)
  4. 4.0 4.1 Ken Hub Rotatores Available: https://www.kenhub.com/en/library/anatomy/rotatores-muscles(accessed 30.1.2022)
  5. Nitz AJ, Peck D. Comparison of muscle spindle concentrations in large and small human epaxial muscles acting in parallel combinations. The American Surgeon. 1986 May 1;52(5):273-7. Available:https://pubmed.ncbi.nlm.nih.gov/2422993/ (accessed 30.1.2022)
  6. Parkhurst TM, Burnett CN. Injury and proprioception in the lower back. Journal of Orthopaedic & Sports Physical Therapy. 1994 May;19(5):282-95. Available:https://www.jospt.org/doi/pdf/10.2519/jospt.1994.19.5.282 (accessed 30.1.2022)