Glenoid version: increased retroversion is associated with which change in ROM?

Glenoid version: increased retroversion is associated with which change in ROM?

• A. Increased External Rotation and Decreased Internal Rotation
• B. Increased Internal Rotation and Decreased External Rotation
• C. No Change in ROM
• D. Increased Abduction Only

Answer: (A)

Glenoid version describes how the socket is oriented in the scapula. When there is increased retroversion, the glenoid fossa tilts more posteriorly. This posterior tilt makes the joint more permissive to external rotation because the articulating surface aligns favorably with the humeral head during external rotation, allowing a larger range before impingement on the anterior rim occurs. At the same time, internal rotation becomes more limited because the posterior tilt brackets the range sooner—the posterior capsule and labral structures are encountered earlier as you rotate internally. So the net effect of greater retroversion is an increase in external rotation with a decrease in internal rotation.

Glenoid version describes how the socket is oriented in the scapula. When there is increased retroversion, the glenoid fossa tilts more posteriorly. This posterior tilt makes the joint more permissive to external rotation because the articulating surface aligns favorably with the humeral head during external rotation, allowing a larger range before impingement on the anterior rim occurs. At the same time, internal rotation becomes more limited because the posterior tilt brackets the range sooner—the posterior capsule and labral structures are encountered earlier as you rotate internally. So the net effect of greater retroversion is an increase in external rotation with a decrease in internal rotation.