06/05/2026
🦴 Mastering Shoulder & Scapular Biomechanics
The shoulder complex is one of the most mobile yet unstable joint systems in the human body. To build true stability, prevent impingement, and optimize upper body movement, we have to look closely at how specific muscles drive scapular and humeral motions.
🔽 1. Depression
The Motion: Pulling the shoulder girdle downward.
Key Muscles Involved: Latissimus dorsi, Pectoralis major, and Pectoralis minor.
🔼 2. Elevation
The Motion: Shrugging or lifting the shoulder girdle upward.
Key Muscles Involved: Trapezius, Levator scapulae, and Serratus anterior.
🔙 3. Retraction
The Motion: Squeezing the shoulder blades back toward the spine.
Key Muscles Involved: Trapezius, Rhomboids, and Latissimus dorsi.
🔜 4. Protraction
The Motion: Reaching forward, moving the shoulder blades away from the spine.
Key Muscles Involved: Serratus anterior and Levator scapulae.
↪️ 5. External Rotation
The Motion: Rotating the arm outward away from the midline.
Key Muscles Involved: Deltoid, Teres minor, and Infraspinatus (critical rotator cuff stabilizers!).
↩️ 6. Internal Rotation
The Motion: Rotating the arm inward toward the midline.
Key Muscles Involved: Deltoid, Pectoralis major, Teres major, and Latissimus dorsi.
💡 Clinical Takeaway:
Whether you are rehabing a rotator cuff tear, correcting a rounded posture, or programming overhead lifts, targeting the right muscle group for these specific biomechanical actions makes all the difference.
📌 Save this post as a quick anatomy reference for your next movement assessment or training session!
What is your go-to exercise for targeting scapular retraction? Let’s discuss in the comments below! 👇
