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Anatomy pictures

Scaleni group - without clavicula
Scaleni group - with clavicula
Scaleni group - lateral
Scaleni group - posterior
Scalenius anterior - anterior
Scaleni anterior - lateral
Scalenius middle - anterior
Scaleni middle - lateral
Scalenius posterior - anterior
Scaleni posterior - lateral
Scaleni posterior - posterior

Referred pain pattern

Muscle Type

  • Phasic in optimal function
  • Can become postural during chronic dysfunction of neck, for example, cases of asthma, habitual hyperventilation breathing


  • Arterial obstruction to arm
  • Compression of brachial plexus (thoracic outlet syndrome)
  • Carpal tunnel syndrome
  • Tingling, numbness in hand
  • Whiplash syndrome
  • Cervical dysfunction
  • Sedentary lifestyle, leading to altered breathing behavior
  • Dysfunctional breathing patterns
  • Loss of vertical dimension of cervical discs
  • Forward head posture


  • Thoracic outlet syndrome


Ear Levels

  • When observing the patient from the back, notice any difference in height of the lower part of the ears
  • If one ear is lower than the other it might indicate tightness of the Scalene muscles and/or in the following muscles:
    • Trapezius
    • Levator Scapulae
    • Sternocleidomastoideus

Neck Tilt

  • If the neck is tilted towards the shoulder, it indicates that the following muscles on the side which the head is tilted towards could be involved:
    • Levator Scapulae
    • Sternocleidomastoideus
    • Scalene
    • Trapezius

Cervical Rotation

  • When standing directly behind the patient, assess whether you are able to see more of the patient's jaw or cheek on one side than the other
  • When the head is more rotated to one side, the following muscles could be involved on the side which the head is rotated towards:
    • Scalene
    • Levator Scapulae
  • The following muscles could be involved on the opposite side in which the head is rotated towards:
    • Sternocleidomastoideus

Possible causes for tension

  • Reduced function of diaphragma, which causes the scaleni to overload in an attempt to compensate due to it facilitating breathing
  • High levels of tension in the latissimus dorsi places tension on the brachial plexus by depressing the entire shoulder girdle, depression of the shoulder girdle may again trigger the scalene to counter the depression by elevating the 1. and 2. ribs, and in so causing tension in the Scalene 

Muscular attachments


Short version

Detailed version

Important functions

  • Facilitates breathing
    • Attaching to the 1.-2. ribs the scalene helps improve inspiration by moving the upper ribs and the pleura cranially, thus expanding the thoracic cavity, thereby increasing inspiration
    • The main muscles of respiration are the diaphragm, external intercostals, internal intercostals, and innermost intercostal muscles
    • Other muscles contributing to breathing are the sternocleidomastodieus, pectoralis major, serratus anterior, latissimus dorsi, internal obliques, external obliques, and transverse abdominal muscles

Notes of clinical importance

Additional Muscles Which Are Affected By The Altered Tension Level

  • If diaphragmatic function is reduced, the scalene may become overloaded due to compensation
  • If the scalenes fix the 1st rib, external intercostals elevate and protract ribs 2-12, thus expanding the thoracic cavity and creating a partial vacuum, causing inflow of air.
  • An important relation to interscapular pain could be entrapment of the dorsal scapular nerve by the scaleni medius. This can particularly be aggrovated during overhead activities. Study


Adson's Test

  • This tests for compression of the subclavian artery
  • A positive test often implicates shortening of the scalene or a 1st rib restriction
  • The therapist locates the radial pulse on the patient's wrist
  • Position the patient's arm in abduction, extension and lateral rotation
  • Have the patient draw a deep breath and hold it while keeping the arm in the same position
  • Have the patient rotate the head to the opposite side (contralateral) from the side being tested
  • Note if there is a drop in the pulse or if the patient complains of parasthesia within a few seconds
  • If any of the two are true then compression of the subclavian artery is probable
  • A similar test can be conducted for testing the pectoralis minor


Deep Ventral Line


Neck flexion

Lateral flexion neck


Extension of neck

Lateral flexion of neck - contralateral side

Depression of 1st and 2nd rib

  • Internal intercostals - 1-11 ribs
  • External intercostals - 1-11 ribs
  • Transversus thoracis - 2nd to 6th ribs



  • Superficial (mostly)


  • Processus transversi C2-C7
    • Anterior: C3-C6
    • Medius: C2-C7
    • Posterior: C5-C7


  • 1. and 2.rib
    • Anterior: 1. rib
    • Medius: 1. rib
    • Posterior 2. rib

Main function

  • Neck
    • Flexion (anterior, medius)
    • Lateral flexion (anterior, medius and posterior)
  • 1. and 2. ribs
    • Elevation

Secondary function

  • Neck: Contralateral rotation

Segmental nerveinnervation

  • C3-C8
    • Anterior: C4-C6
    • Medius: C3-C8
    • Posterior: C6-C8

Arterial supply

  • Cervical artery