• Origin

First rib and its costal cartilage (at the junction)

• Insertion

Inferior surface of the middle third of the clavicle (subclavian groove)

• Agonist(s)

- Pectoralis minor (assists in scapular depression and stabilization),

- Lower fibers of trapezius (in scapular depression and clavicle stabilization).

• Antagonist(s)

- Upper trapezius (in clavicular elevation),

- Sternocleidomastoid (in clavicular elevation during respiration).

• Function

Stabilizes and depresses the clavicle. Helps protect underlying neurovascular structures (subclavian vessels and brachial plexus).

Assists in drawing the clavicle anteriorly and inferiorly. Acts as a cushion against excessive movement of the clavicle during shoulder and arm activity.

TRIGGER POINT(S)

• Location

Trigger points are commonly located just inferior to the clavicle, near its medial third—deep to the clavicle and lateral to the sternum.

• Pain Referral Pattern

Pain may refer to the anterior shoulder, down the anterior arm, and into the radial aspect of the forearm and hand.

Can mimic symptoms of thoracic outlet syndrome by irritating nearby neurovascular structures.

Localized tenderness under the clavicle may be present.

💢

Potential Causes

• Poor posture, especially rounded shoulders and forward head posture.

• Heavy lifting or repetitive shoulder depression (e.g., carrying heavy bags).

• Traumatic injury to the shoulder or clavicle (e.g., falls or impact).

• Tight chest muscles creating fascial restrictions.

• Prolonged use of crutches or leaning on elbows while seated.

✅

Prevention Tips

• Practice good posture with shoulders gently retracted and head aligned over the spine.

• Avoid prolonged or repeated downward pressure on the shoulders (e.g., heavy shoulder straps).

• Stretch and mobilize the upper chest and clavicle region regularly.

• Strengthen postural stabilizers such as rhomboids and lower trapezius.

• Use proper lifting techniques and reduce loads that stress the shoulder girdle.