Shoulder posterior internal impingement in the overhead athlete

Area of Science:

• Orthopedics
• Sports Medicine
• Biomechanics

Background:

• Posterior internal impingement (PII) of the glenohumeral joint is a frequent source of shoulder pain in overhead athletes.
• This condition differs significantly from typical outlet impingement.
• It manifests as posterior shoulder pain during extreme external rotation and abduction, such as in the cocking phase of throwing.

Purpose of the Study:

• To review current concepts in the pathophysiology, evaluation, and treatment of posterior internal impingement.
• To highlight the evolving understanding of this condition.

Main Methods:

• This is a current concepts review.
• It synthesizes existing knowledge on PII.
• A high index of suspicion is recommended for diagnosis.

Main Results:

• Posterior internal impingement involves impingement between the supraspinatus/infraspinatus and the glenoid rim.
• The exact precipitating factors, causes, presentation, and optimal treatment methods are still under investigation.
• Understanding of PII continues to evolve.

Conclusions:

• Posterior internal impingement is a specific pathology requiring careful diagnosis in overhead athletes.
• Further research is essential to establish definitive understanding and treatment protocols.
• This review provides a current overview of PII pathophysiology, evaluation, and treatment strategies.