Scalenes Anatomy: Origins, Insertions, Actions, Innervations

Scalenes Anatomy Study

Scalenes Anatomy

Scalene Muscle Group:

Synergist: Sternocleidomastoid, Longus colli and capitis

Antagonist: Semispinalis capitis and cervicis, Splenius capitis and cervicis, Spinalis cervicis, Interspinales, Longissimus cervicis, Iliocostalis cervicis, Multifidus.

Scalenus Anterior

Origin: Anterior tubercles of the  transverse processes of (C3-C6)
Insertion: Scalene tubercle and cranial crest of first rib
Action: Flexion of the cervical spine, Lateral flexion of the cervical spine,
Innervation: Ventral rami of
(C3-C8)
Blood Supply: Branches of the cervical artery

Primary Actions of the Scalenus Anterior:

1. Flexion of the cervical spine when acting bilaterally

  • Agonists:Longus Colli, Scalenus Medius
  • Antagonists: Longissimus Cervicis, Iliocostalis Cervicis, Spinalis Cervicis, Splenius Cervicis, Semispinalis Cervicis

2. Lateral Flexion of the cervical spine when acting unilaterally

  • Agonists: Scalenus Medius, Scalenus Posterior, Iliocostalis cervicis, Splenius Cervicis, Semispinalis Cervicis
  • Antagonists: Scalenus Anterior, Scalenus Posterior, Iliocostalis Cervicis, Splenius Cervicis, Semispinalis Cervicis on opposite side

Secondary Actions of the Scalenus Anterior:

1. Assists with contralateral rotation of the cervical spine when acting unilaterally

  • Agonists: Semispinalis Cervicis, Multifidus,
  • Antagonists:  Semispinalis Cervicis, Multifidus on opposite side

2. Assists with forced inspiration by elevating first rib

  • Agonists: Serratus Posterior Superior, Levatores Costarum Brevis, Levatores Costarum Longi
  • Antagonist: Serratus Posterior Inferior, Transversus Abdominis

Scalenus Medius

Origin: Posterior tubercles of the transverse processes of (C2-C7)
Insertion: Cranial surface of the first rib
Action: Flexion of the cervical spine, Lateral flexion of cervical spine
Innervation: Ventral rami of (C3-C8)
Blood Supply: Branches of the cervical artery

Primary Actions of the Scalenus Medius:

1. Flexion of the cervical spine when acting bilaterally

  • Agonists: Longus Colli, Scalenus Anterior, Superior Oblique, Inferior Oblique
  • Antagonists: Longissimus Cervicis, Iliocostalis Cervicis, Spinalis Cervicis, Splenius Cervicis, Semispinalis Cervicis

2. Lateral flexion of the cervical spine when acting unilaterally

  • Agonists: Scalenus Anterior, Scalenus Posterior, Iliocostalis Cervicis, Splenius Cervicis, Semispinalis Cervicis
  • Antagonists: Scalenus Anterior, Scalenus Posterior, Iliocostalis Cervicis, Splenius Cervicis, Semispinalis Cervicis on opposite side

Secondary Actions of the Scalenus Medius:

1. Assists with contralateral rotation of the cervical spine when acting unilaterally

  • Agonists: Semispinalis Cervicis, Multifidus
  • Antagonists: Semispinalis Cervicis, Multifidus on opposite side

2. Assists with forced inspiration by elevating the first rib

  • Agonists: Serratus Posterior Superior, Levatores Costarum Breves, Levatores Costarum Longi,
  • Antagonists: Serratus Posterior Inferior, Transversus Abdominis

Scalenus Posterior

Origin: By tendons from the posterior tubercles of  the transverse processes of (C4–C6)
Insertion: Outer surface of 2nd rib
Action: Lateral flexion of the neck
Innervation: Ventral rami of (C3-C8)
Blood Supply: Branches of the cervical artery

Primary Actions of the Scalenus Posterior:

1. Lateral flexion of the cervical spine when acting unilaterally

  • Agonists: Scalenus Anterior, Scalenus Medius, Iliocostalis Cervicis, Splenius Cervicis, Semispinalis Cervicis
  • Antagonists: Scalenus Anterior, Scalenus Medius, Iliocostalis Cervicis, Splenius Cervicis, Semispinalis Cervicis on opposite side

Secondary Actions of the Scalenus:

2. Assists with contralateral rotation of the cervical spine when acting unilaterally

  • Agonists: Semispinalis Cervicis, Multifidus
  • Antagonists: Semispinalis Cervicis, Multifidus on opposite side

3. Assists with forced inspiration by elevating the second rib

  • Agonists: Serratus Posterior Superior, Levatores Costarum Breves,  Levatores Costarum Longi
  • Antagonists: None

For more information see: Scalenes Muscles Pain and Symptoms


Recommended Anatomy Books

Anatomy Coloring Book
coloring_book

The Anatomy Coloring Book is one of the best study and reference books for beginning anatomy students. The diagrams are clearly labeled and allow you to see the relationship and placement of the various structures of the body. You will also be surprised how the act of coloring will help with recall. But this is not just a beginners book, it is also great for practitioners and therapists to have on hand to use with clients and patients to use as a visual reference.

Basic Clincal Massage Therapy

basic_clinical_massa

Out of the scores of books in my office Basic Clinical Massage Therapy is by far the most referenced book in my library. The musculoskeletal system is overlaid on human models allowing you to learn the precise location, origin and insertions of each muscle. The models are pictured in various poses throughout the book which also helps you visualize muscles in motion and their actions relationship with the skeletal structure and other muscles. Though it is written for massage therapists, it is an excellent book for anyone who wants to learn about the muscular system. MT’s will benefit from recommended treatments for each muscle.

 

References:

The Trigger Point Therapy Workbook – Claire Davies, Amber Davies, and David G. Simons

Basic Clinical Massage Therapy: Integrating Anatomy and Treatment – James H. Clay and David M. Pounds

Trigger Point Therapy for Myofascial Pain – Donna Finando and Steven Finando

Massage Therapy Principles and Practice – Susan Salvo

Theory & Practice of Therapeutic Massage – Mark Beck

 

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