Scalene Muscles

The scalene muscles are comprised of the scalenus anterior, the scalenus medius, and the scalenus posterior.

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: Same muscles opposite side

  • Semispinalis Cervicis
  • Multifidus

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
Anterior Scalene

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

  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: Same muscles on opposite side

  • Scalenus Anterior
  • Scalenus Posterior
  • Iliocostalis Cervicis
  • Splenius Cervicis
  • Semispinalis Cervicis

Secondary Actions of the Scalenus Medius:

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

  Agonists:

  • Semispinalis Cervicis
  • Multifidus

  Antagonists: Same muscles on opposite side

  • Semispinalis Cervicis
  • Multifidus

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
Middle Scalene Muscle

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: Same muscles on opposite side

  • Scalenus Anterior
  • Scalenus Medius,
  • Iliocostalis Cervicis
  • Splenius Cervicis
  • Semispinalis Cervicis

Secondary Actions of the Scalenus Posterior:

2. Assists with forced inspiration by elevating the second rib

  Agonists:

  • Serratus Posterior Superior
  • Levatores Costarum Breves,
  • Levatores Costarum Longi

  Antagonists: None

Posterior Scalene Muscle

For pain and symptoms information see: Scalenes Muscles Pain and Symptoms

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Donna Martin

Massage Therapist Owner: thewellnessdigest.com Twelve years of experience working with clients with chronic pain, post injury pain, and post surgery pain. Muscle dysfunction is often overlooked but can hold the key to many pain conditions.

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