The Pec Major: Part 1 - Anatomy of a Beautiful Muscle 💪✨ The Anatomy 🔬 The pec major has 3 heads: 1️⃣ Clavicular head (upper pec) – Attaches to medial half of clavicle 2️⃣ Sternocostal head (mid pec) – Attaches to sternum ribs 2-6 3️⃣ Abdominal head (lower pec) – Attaches to rectus sheath (can vary or be absent!) All three converge to insert on the humerus (arm bone)! The Functions 💪 All 3 heads work together for: ✅ Internal rotation of shoulder ✅ Adduction ✅ Horizontal adduction (the most lo

81K views · 2.3K reactions | Fiber Orientation in the Pec Major #chestday #muscle #anatomy | Institute of Human Anatomy | Facebook