Pectoralis Minor Trigger Points:

The pectoralis minor muscle is the little brother of the pectoralis major muscle. Like all little brothers, the pectoralis minor wants to do everything that  big brother does, so it’s no surprise that trigger points in these two muscles have almost identical referred pain patterns.

These pain patterns start in the front of shoulder and can extend down the inside of the arm, elbow, forearm, palm of the hand, and into the pinky, ring, and middle fingers.

Not to be outdone by big brother, a tense pectoralis minor muscle can also entrap nerves in the armpit region that cause pain, numbness, and tingling to travel down the arm and into the hand.

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The Pectoralis Minor Muscle

Location: The pectoralis minor is a small, thick muscle that lies in the chest region near the shoulder, underneath the larger pectoralis major muscle.

Function: This muscle functions to stabilize the shoulder girdle against the rib cage during downward thrusting movements of the arm, like when using crutches, chopping wood, or raising oneself out of a pool with your arms.

Muscle Attachments & Structure: The pectoralis minor originates on the coracoid process on the front of the scapula (shoulder blade) and splits into three sections that travel diagonally downward and medial to attach to the 3rd, 4th, and 5th ribs.

Muscle Actions: Contraction of the pectoralis muscle pulls the shoulder blade downward (depression) and forward (protraction) on the ribcage. Conversely, if the shoulder is held in place by the levator scapula and trapezius muscles, contraction of the pectoralis minor can elevate the upper ribcage and assist in inhalation.

Biomechanical Considerations: Chronic tension in the pectoralis minor can produce “winging of the scapula” in which the vertebral edge and lower tip of the scapula stick out from the rib cage and become visually prominent.

Tension in this muscle can also cause it to compress (entrap) the nerves of the brachial plexus in the shoulder region, producing neurogenic pain and numbness that is experienced in the forearm, hand, and fingers. It may also restrict blood flow to arm by compressing the axillary artery. Because of these entrapments, trigger point activity in this muscle can be a major contributor to thoracic outlet syndrome (along with scalene trigger points).

The Pectoralis Minor Trigger Point

Pectoralis Minor Muscle Pain

The diagram above shows the referred pain pattern associated with the primary trigger point. The pain concentrates in the anterior shoulder region, though it may also extend across the chest. It will also frequently travel down the inside the upper arm, elbow,  forearm (on the pinky side). It can also occasionally refer to the palm, and into the pinky, ring and middle fingers.

This pain pattern is almost identical to that produced by the trigger points in the clavicular division of the pectoralis major.

Pectoralis Minor Symptoms & Disorders

Clients with an active pectoralis minor trigger point will present with any or all of the following symptoms or clinical findings:

Pain in the anterior shoulder region, extending into the chest region when severe.

Pain that travels down the inside of the arm to the pinky, ring, and middle fingers.

Like with the pectoralis major trigger points, if this pain is experienced in the left shoulder, chest, and arm, it can be confused with the pain from heart disease or a heart attack.

Pain on the inside aspect of the elbow, that mimics the pain of medial epicondylitis or “golfer’s elbow”

Numbness or tingling in the forearm, hand, and fingers, like that associated with carpal tunnel syndrome and/or thoracic outlet syndrome.

A weak or absent pulse at the wrist of the affected arm.

Difficulty in reaching forward and up with the affected arm.

A depressed shoulder girdle combined with winging of the scapula on the affected side.

What Causes Pectoralis Minor Trigger Points?

The following events or activities may activate or reactivate the pectoralis minor trigger points:

Trauma to the chest from a car accident

Whiplash from a car accident

Fracture or bruising of the upper ribs

Prolonged use of crutches

Hyperventilation or heavy breathing

Emotional or mental stress

Carrying a heavy backpack or purse over the shoulder

The head-forward, sunken-chest posture that is common in people that work at computers for long periods.

Previous or intermittent cardiac pain from a heart attack or angina pectoris.

Related Disorders

Thoracic Outlet Syndrome

Medial Epicondylitis or “Golfer’s Elbow”

Carpal Tunnel Syndrome

Cervical Radiculopathy or herniated disk

Cardiac Pain

Treatment of Pectoralis Minor Trigger Points

Important Note to the Reader: If you, or a client, is experiencing left sided shoulder and arm pain, it is imperative that a examination by a cardiologist be done immediately. Trigger point referred pain from the pectoralis muscles may occur secondarily to underlying heart disease, which must be ruled out or treated before trigger point therapy is indicated.