1st Rib (Bone)

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Left clavicle (inferior view)¹

Anatomy

Types of cervical rib:

• Type I: complete cervical rib articulates with the first rib or manubrium of sternum²
• Type II: incomplete cervical ribs with a free end expanded to form a bulbous tip²
• Type III: an incomplete rib that is continued by a fibrous band²
• Type Iv: rib that appears as a short bar of bone with a length of a few millimeters beyond the C7 TP²

Variations

• Type I: complete cervical rib articulates with the first rib or manubrium of sternum²
• Type II: incomplete cervical ribs with a free end expanded to form a bulbous tip²
• Type III: an incomplete rib that is continued by a fibrous band²
• Type IV: rib that appears as a short bar of bone with a length of a few millimeters beyond the C7 TP²

Costal Cartilage

The costal cartilage of the 1st rib is at the anterior aspect of the 1st rib and it articulates with the sternum at the 1st sternocostal joint³.

Muscle attachments

Table 1: Muscular Origins of 1st Rib

Muscle	Origin	Insertion	Innervation	Action
Serratus anterior	1-9 Ribs	Superior angle of Scapula (costal and dorsal surfaces) Medial border of scapula (costal surface) Medial border of scapula (costal surface) Inferior angle of Scapula (costal & dorsal surfaces)	Long thoracic n. C5 - C7	Superior part: Lowers raised arm Entire mm.: Protraction, Rib elevation (with fixed shoulder) Inferior part: Rotates scapula laterally forward
Subclavius	1st rib	Clavicle (inferior surface)	N. to subclavius C5 - C6	SCJ: Stabilization

Table 2: Muscular Insertions on 1st Rib

Muscle	Origin	Insertion	Innervation	Action
Anterior scalene	Anterior tubercle of TP of C3-C6	Scalene tubercle of 1st Rib	Anterior Rami C4 - C6	Mobile ribs: Elevates ribs during forced inspiration Fixed ribs (unilateral): I/L C/s sidebend (unilateral) Fixed ribs (bil): C/s flexion, Cervical lateral stabilization
Iliocostalis thoracis	Ribs 7-12	Ribs 1-6	Spinal nn. Posterior rami (lateral br.) C8 - L1	Bilateral: Extends spine Unilateral: Spine ipsilateral sidebend
Levatores cosatrum breves	C7-T11 TP	Costal angle of next inferior rib	Spinal nn. (posterior rami)	Bilateral: Thoracic extension Unilateral: Thoracic ipsilateral sidebend, contralateral rotation
Levatores costarum longi	C7-T11 TP	Costal angle of rib 2 segments inferior	Spinal nn. (posterior rami)	Bilateral: Thoracic extension Unilateral: Thoracic ipsilateral sidebend, contralateral rotation
Middle scalene	C1-C2 TP Posterior tubercle of TP of C3-C7	1st Rib (posterior to groove for subclavian a.)	Anterior Rami C3 - C8	Mobile ribs: Elevates ribs during forced inspiration Fixed ribs (unilateral): I/L C/s sidebend (unilateral) Fixed ribs (bil): C/s flexion, Cervical lateral stabilization

Elevation

1st rib elevation is a cause of Thoracic Outlet Syndrome⁴

Hypomobility

1st Rib hypomobility or restriction can be caused by:

• 1st rib subluxation at costotransverse joint

Can result in secondary pathologies, such as:

• Thoracic outlet syndrome (TOS)

• Tests:

  • Cervical Rotation Lateral Flexion
  • Costoclavicular Test

Assessment

Presentation

• Neck and vague ipsilateral upper limb distribution of symptoms (pain and paresthesia)⁵
  • Especially ulnar nerve distribution

Aggravations

Functional

• Restricted and aggravating Neck activity⁵
  • BIL neck rotations⁵
  • BIL lateral-flexions⁵
  • BIL combined movements with extension were the main aggravating activities with restricted range of movement⁵
• Shoulder girdle⁵
• Respiratory activities⁵

Assessment

Onset

Onset was associated with direct traumas, whiplash, shoulder girdle efforts, such as carrying heavy bags or pulling on ipsilateral arm, and shoulder surgery⁵

Mobilization

Safety

• If pain/paresthesias w/ rib mobs, authors discourage use⁶
• However if associated w a release phenomenon (nerve function regaining), continue doing mobilizations⁶

Indication

• Thoracic outlet syndrome due to costoclavicular space compression⁶

Release

I learned this 1st rib technique from Brad Jones⁷. It could be considered a mobilization with movement (MWM) but I consider it to be more like a release since at the end of the mobilization, I hold the position and wait for the tissues around the 1st rib to release.

• Patient in supine
• Stand on the ipsilateral side facing the patient’s feet
• Palpate the patient’s ipsilateral clavicle and follow it medially.
• Move posteriorly from the clavicle into the posterior triangle of the neck
• Place your fingertips on the 1st rib and scalenes
• Grip the patient’s upper arm
• Drive the 1st rib inferiorly while you bring the shoulder into abduction
• When you reach the end feel, hold the inferior glide and the abduction position for a few seconds until it releases.

Dosage: ~2x10

References

1.

Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/

2.

Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS. Thoracic outlet syndrome: A controversial clinical condition. Part 1: Anatomy, and clinical examination/diagnosis. The Journal of Manual & Manipulative Therapy. 2010;18(2):74-83. doi:10.1179/106698110X12640740712734

3.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.

4.

Dutton M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 5th ed. McGraw Hill Education; 2020.

5.

Mastromarchi P, May S. First rib dysfunction in patients with neck and shoulder pain: A Delphi investigation. The Journal of Manual & Manipulative Therapy. 2021;29(3):181-188. doi:10.1080/10669817.2020.1824470

6.

Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS. Thoracic outlet syndrome: A controversial clinical condition. Part 2: Non-surgical and surgical management. The Journal of Manual & Manipulative Therapy. 2010;18(3):132-138. doi:10.1179/106698110X12640740712338

7.

Jones B. B Project Foundations. b Project; 2025.