What does the posterior sternoclavicular ligament primarily resist?

• A. Posterior displacement
• B. Anterior displacement
• C. Medial movement
• D. Elevation

Answer: (B)

The posterior sternoclavicular ligament is primarily responsible for resisting anterior displacement of the clavicle. This ligament plays a critical role in maintaining the stability of the sternoclavicular joint, which is the joint between the sternum and the clavicle.

When the arm is raised or during certain movements, this ligament helps ensure that the clavicle remains in its proper position, preventing it from moving too far forward (anterior displacement). Proper functioning of this ligament is essential for shoulder stability and biomechanical efficiency during upper extremity movements. Understanding the role of the posterior sternoclavicular ligament is important for athletic trainers in diagnosing and managing shoulder injuries that can arise from overstretching or damage to this ligament.