Pectoralis Major Injury: Anatomy, Mechanisms, Symptoms, and Recovery

Anatomy

The pectoralis major is a large, fan-shaped muscle with two heads:

• Clavicular head: Medial clavicle → lateral lip of bicipital groove.
• Sternal head: Sternum, costal cartilages 1–6, external oblique aponeurosis → same insertion.

Actions: Shoulder flexion, adduction, internal rotation; assists in forced inspiration.

Injury Mechanisms

• Acute rupture: Eccentric overload during bench press, wrestling, football block. Usually at musculotendinous junction or tendon avulsion.
• Chronic tendinopathy: Repetitive microtrauma.
• Direct trauma/contusion.

Symptoms

• Sudden "tearing" sensation, pain, swelling, ecchymosis (chest/upper arm).
• Weakness in adduction/internal rotation.
• Visible deformity: loss of anterior axillary fold, bunched muscle belly.

Treatment

• Partial tears/low-demand patients: Conservative (rest, PT, NSAIDs).
• Complete tears/active individuals: Surgical repair (anatomic tendon reattachment) within 2–3 weeks for best outcomes.

Rehabilitation

Progressive: immobilization → passive/active ROM → strengthening (isometric → isotonic) → functional/sport-specific. Full recovery: 4–6 months.