Pectoralis Minor

Origin, Insertion, Action, Innervation

Origin: Anterior surfaces and superior borders of ribs 3–5 (sometimes 2–4), near the costochondral junctions
Insertion: Medial border and superior surface of the coracoid process of the scapula
Action:
Primary: Anterior tilt of the scapula, protraction (abduction) of the scapula
Depression of the shoulder girdle (pulls the coracoid inferiorly)
Elevation of ribs 3–5 during forced inspiration (accessory muscle of respiration, when the scapula is fixed)
Innervation: Medial pectoral nerve (C8–T1), sometimes with contributions from the lateral pectoral nerve (C5–C7)

Palpation Guide

Client position: Supine with the arm at the side.
Landmark sequence:

Locate the coracoid process — palpate inferior to the lateral third of the clavicle, in the deltopectoral triangle. The coracoid is a bony projection pointing anteriorly and laterally, approximately 2 cm inferior and medial to the acromion. It is the insertion of pectoralis minor.
From the coracoid, pectoralis minor runs inferomedially, deep to the pectoralis major, to the ribs (3–5). You must palpate through the overlying pectoralis major to access it.
To access the muscle belly, abduct and slightly laterally rotate the client's arm (to relax pectoralis major). Press through the relaxed pectoralis major fibers, directing your pressure posteriorly and medially toward the rib cage. The pectoralis minor fibers run at a different angle than pectoralis major, which helps distinguish them.
The muscle is best palpated near the coracoid process, where it is most superficial relative to the overlying pectoralis major.

Tissue feel: Thin and flat compared to pectoralis major. When accessed through the major, it feels like a taut band running from the coracoid toward the ribs. In a shortened state, it feels like a tight cord from the coracoid into the chest wall.
Confirmation test: Ask the client to protract the scapula (push the shoulder forward toward the ceiling while supine). You will feel pectoralis minor contract under pectoralis major, pulling the coracoid anteriorly.
Common errors:
Palpating pectoralis major and believing you are on pectoralis minor — the minor lies deep. You must sink through the major or palpate near the coracoid where the minor is most accessible.
Pressing on the coracoid process too aggressively — the coracoid is tender in many clients, and the musculocutaneous nerve, biceps short head, and coracobrachialis also attach here.
Not differentiating pectoralis minor from the subclavius — subclavius is a small muscle between the clavicle and first rib, superior to pectoralis minor.

Trigger Point Referral

Common TrP locations: The primary TrP is in the mid-belly, approximately midway between the coracoid process and the rib attachments. A secondary TrP is near the coracoid insertion.
Referral pattern: Refers to the anterior shoulder and the anterior chest (over the pectoralis major region). May extend down the medial arm, overlapping with pectoralis major referral.
Clinical significance: The anterior chest referral overlaps with pectoralis major TrP patterns and, more importantly, with cardiac pain referral. The key differentiator from pectoralis major TrPs: pectoralis minor TrPs are reproduced by deep palpation through the major toward the ribs, not by superficial chest palpation. Always rule out cardiac pathology first in any anterior chest pain.

Trigger point referral diagram — coming soon

Image coming soon. For visual reference, see [Pectoralis Minor at TriggerPoints.net](http://www.triggerpoints.net/muscle/pectoralis-minor).

Clinical Notes

Innervation significance:

The medial pectoral nerve (C8–T1) passes through or near the pectoralis minor muscle belly on its way to the pectoralis major. A hypertonic pectoralis minor can compress its own nerve — a localized entrapment that produces chest wall pain and pectoralis major weakness.

Common conditions:

One of Janda's "tight" muscles in conditions/upper-crossed-syndrome. Pectoralis minor shortening tilts the scapula anteriorly, rotates it downward, and protracts it. This narrows the subacromial space (by tilting the acromion anteriorly over the supraspinatus tendon) and contributes to conditions/subacromial-impingement.
Direct contributor to conditions/thoracic-outlet-syndrome — the brachial plexus and axillary artery pass deep to the pectoralis minor (under the coracoid process) in the subcoracoid space. A shortened pectoralis minor compresses the neurovascular bundle against the rib cage, producing the pectoralis minor (hyperabduction) variant of TOS.
Wright's test (hyperabduction test) specifically assesses pectoralis minor compression of the neurovascular bundle.
An accessory respiratory muscle — chronic overuse in chest-breathers leads to shortening, perpetuating the forward-shoulder posture.

What you'll typically find:

Shortened in the vast majority of desk workers, alongside the pectoralis major. The scapulae are anteriorly tilted and protracted, and the coracoid processes are prominent on palpation.
The pectoralis minor length test (described in Assessment) is frequently positive bilaterally. Many clients cannot achieve full supine horizontal abduction because the pectoralis minor holds the scapula in anterior tilt.
In clients with TOS symptoms, palpation of the pectoralis minor near the coracoid may reproduce arm numbness and tingling.

Treatment effects:

Sustained compression through the pectoralis major toward the rib attachments of pectoralis minor. Hold TrPs for 30–60 seconds. The client may report anterior chest or shoulder referral.
Pin-and-stretch: compress the muscle while passively retracting and posteriorly tilting the scapula (by bringing the shoulder into horizontal abduction and slight extension).
Post-treatment, scapular position should visibly improve — less anterior tilt, more retraction. The coracoid process should be less prominent anteriorly.

Cautions:

The brachial plexus and axillary artery pass deep to pectoralis minor in the subcoracoid space. Do not apply deep pressure toward the axilla — direct your pressure posteriorly toward the ribs, not laterally toward the axilla.
The coracoid process has multiple tendon attachments (pectoralis minor, coracobrachialis, biceps short head) and is often tender. Palpate gently.
Same draping and consent considerations as pectoralis major — essential in all clients, particularly female clients.

Postural significance:

Pectoralis minor is arguably the most important muscle in upper crossed syndrome from a scapular perspective. It is the primary muscle that anteriorly tilts the scapula. Anterior scapular tilt is what narrows the subacromial space and creates the mechanical precondition for supraspinatus impingement. Lengthening pectoralis minor and strengthening lower trapezius and serratus anterior to posteriorly tilt the scapula is the core scapular correction strategy.

Clinical pearl:

Pectoralis minor length directly predicts subacromial impingement risk. Measure the distance from the treatment table to the posterior aspect of the acromion while the client lies supine with arms at the side. Greater than 2.5 cm suggests significant pectoralis minor shortening. This "pec minor index" is a quick, reproducible screen that tells you whether the scapular position is contributing to the client's shoulder pain.

Assessment

Manual muscle testing:

Scapular protraction/anterior tilt: Client supine. Ask the client to push the shoulder toward the ceiling (protraction). Apply downward and posterior resistance. This tests pectoralis minor directly.

Stretch test:

Pectoralis minor length test: Client supine with arms at the side. Measure the distance from the treatment table to the posterior acromion. Greater than 2.5 cm indicates shortening. Compare bilaterally.

Related special orthopedic tests:

Wright's hyperabduction test — hyperabduct the arm overhead and monitor the radial pulse; loss of pulse suggests pectoralis minor compression of the subclavian artery (TOS)
Scapular dyskinesis assessment — excessive anterior tilt during arm elevation suggests pectoralis minor shortening

Muscle Groups

Scapular protractors (functional):

anatomy/muscles/serratus-anterior — primary protractor
Pectoralis minor (this article) — protracts with anterior tilt

Scapular downward rotators (functional):

Accessory respiratory muscles (functional):

Upper crossed syndrome — "tight" group (clinical):

Pectoral nerve group (innervation):

anatomy/muscles/pectoralis-major — medial and lateral pectoral nerves
Pectoralis minor (this article) — medial pectoral nerve

Related Muscles

Synergists for scapular protraction:

anatomy/muscles/serratus-anterior — protracts without anterior tilt (healthier scapular position)

Antagonists:

anatomy/muscles/lower-trapezius — posteriorly tilts and depresses the scapula; directly opposes pectoralis minor's anterior tilt
anatomy/muscles/middle-trapezius — retracts the scapula
anatomy/muscles/rhomboids — retract the scapula

Clinically related:

anatomy/muscles/pectoralis-major — overlies pectoralis minor; both are shortened in upper crossed syndrome

Key Takeaways

The primary muscle responsible for scapular anterior tilt — lengthening it is the key scapular correction for subacromial impingement.
Directly compresses the brachial plexus and axillary artery in the subcoracoid space — central muscle in the hyperabduction variant of TOS.
The pec minor index (table-to-acromion distance) is a quick, reproducible screen for pectoral shortening and impingement risk.