Pectoralis Major Muscle Tear: Symptoms, Causes, Classification, and Treatment Options

Pectoralis Major Tear

A rupture of the pectoralis major tendon (usually at humeral insertion) or muscle belly. Rare but increasing with weight training. 90% occur in men 20–50 during bench press (eccentric phase).

Anatomy

• Two heads: clavicular (upper) and sternocostal (lower). Converge to flat tendon inserting on lateral lip of bicipital groove.
• Actions: horizontal adduction, internal rotation, shoulder extension/adduction.

Injury Mechanism

• Forceful eccentric contraction with arm abducted/externally rotated (bottom of bench press).
• Direct trauma (football, wrestling).
• Steroid use → tendon weakening (collagen changes).

Symptoms

• Sudden "tear" or "pop" sensation in chest/axilla.
• Immediate pain, weakness, inability to push.
• Ecchymosis: chest, upper arm, forearm (gravity tracks blood).
• Swelling, deformity: "dropped" pec, axillary fullness (retracted muscle).
• Palpable defect at tendon insertion.

Classification (Tietjen)

• Type 1: Tendon avulsion from humerus (most common, best surgical candidate).
• Type 2: Musculotendinous junction tear.
• Type 3: Muscle belly tear.
• Type 4: Muscle avulsion from sternum (rare).

Diagnosis

• Clinical: history, ecchymosis, deformity, weakness on resisted adduction/IR.
• MRI (gold standard): confirms location, grade, retraction.
• Ultrasound: dynamic, cheaper, operator-dependent.

Treatment

Non-Operative

• Indicated: Type 3/4, low-demand patients, elderly, high surgical risk, partial tears.
• Protocol: Sling 2–3 weeks → passive ROM → active → progressive strengthening at 12 weeks.
• Outcome: 10–20% strength deficit, cosmetic deformity, possible cramping.

Operative (Preferred for Active, Type 1/2)

• Timing: Acute (<2–3 weeks) best; chronic possible with grafts.
• Technique: Suture anchors, bone tunnels, or cortical buttons. Repair to anatomic footprint.
• Rehab: Protected 6 weeks → progressive ROM/strength → return to sport 5–6 months.
• Outcome: 90%+ return to pre-injury level; near-normal strength.

Rehabilitation Phases

• Phase I (0–6 weeks): Protect repair. Sling, passive ROM (flexion <90°, ER <30°), scapular setting.
• Phase II (6–12 weeks): Active ROM, submax isometrics, scapular strengthening.
• Phase III (3–4 months): Progressive resistance (bands → dumbbells), closed-chain.
• Phase IV (4–6 months): Plyometrics, sport-specific, return-to-play criteria.

Prevention

• Balanced push/pull programming.
• Eccentric control on bench (3-second lower).
• Avoid excessive range (touching chest with heavy load if shoulder extension limited).
• Limit steroid use.
• Progressive overload – no ego lifting.