10/15/2025
⚾🏐 Shoulder Rotation Deficits & Injury Risk in Overhead Athletes
Dr. Louis Rizio MD | Sports Surgery Specialist
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What Is GIRD?
• Glenohumeral Internal Rotation Deficit (GIRD) = loss of internal rotation in the dominant shoulder.
• Common in overhead athletes: baseball, tennis, volleyball, cricket.
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Why It Matters
• A >15–20° deficit in internal rotation increases risk of shoulder & elbow injuries.
• Reduced total rotational motion (TROM) = higher stress on the joint.
• Alters throwing mechanics → increased torque and impingement risk.
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Key Stats
• ⚠️ ≥25° loss of IR = up to 4× greater injury risk in high school baseball players.
• 🏐 Volleyball players with ≥17° GIRD & ≥5° TROM asymmetry → more shoulder pain.
• GIRD worsens over years of overhead play & is influenced by prior injuries.
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Common Injuries Linked to GIRD
• Rotator cuff tendinopathy or partial tears
• SLAP/labral injuries
• Posterior shoulder tightness & impingement
• UCL strain at the elbow
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Prevention & Management
• 🧘♂️ Sleeper & cross-body stretches
• 💪 Posterior cuff mobility + scapular control work
• 🩺 Regular screening of shoulder rotation during season
• ⚖️ Maintain total shoulder motion within 5° of non-throwing side
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Pro Insight:
Not all GIRD is “bad.” Some loss of IR is a normal throwing adaptation — the key is balance and monitoring total motion, not just one direction.
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Take-Home Message
➡️ GIRD matters — small rotation losses can lead to big injury risks.
➡️ Early detection, consistent mobility work, and season-long monitoring protect performance and longevity.