At the SSI Sports Science Conclave 2025, one of the most insightful and clinically relevant sessions focused on a silent yet widespread injury risk among throwers — Glenohumeral Internal Rotation Deficit (GIRD). The session was delivered by Dr. Renu Londhe, Consultant Physiotherapist, Shoulder & Sports Injury Department, Deenanath Mangeshkar Hospital, Pune, who offered a deep dive into the biomechanics of throwing and the devastating impact of untreated shoulder imbalance.
Throwing Begins from the Ground: The Power of the Kinetic Chain
Dr. Londhe emphasized that throwing is not just a shoulder action — it is a full-body movement driven by the kinetic chain. Every throw begins with:
• The reaction force from the ground
• Transfer of energy through the feet, legs, hips, trunk, and finally the shoulder
• Any break in this chain increases stress on the shoulder joint
“If force is not efficiently transferred from the lower body, the shoulder is forced to compensate — and that’s where injuries begin,” she explained.
The Crucial Role of the Scapula and Force Couples
A major focus of the session was on scapular balance and force couples — coordinated muscle groups that stabilize and move the shoulder:
• The Trapezius and Serratus Anterior act as a key force couple
• The Supraspinatus and Deltoid must remain balanced
• The Supraspinatus neutralizes and stabilizes the humeral head, preventing unwanted translation
Any weakness or imbalance in these force couples disrupts optimal shoulder movement, leading to:
• Shoulder instability
• Increased friction
• Eventual dislocation or tendon injury
What is GIRD and Why is it Dangerous?
Glenohumeral Internal Rotation Deficit (GIRD) is a condition seen commonly in throwers and overhead athletes, where:
• Internal rotation of the shoulder is significantly reduced
• External rotation increases abnormally
• The total arc of shoulder motion (normally ~180°) becomes distorted
Dr. Londhe demonstrated how:
• Normal athletes maintain balanced rotation
• Pitchers and throwers show excessive external rotation and restricted internal rotation
• This imbalance directly alters throwing biomechanics
Ligaments Under Stress: AIGHL and PIGHL
The session also explained how shoulder ligaments adapt — and often suffer — during repeated throwing:
• AIGHL – Anterior Inferior Glenohumeral Ligament
• PIGHL – Posterior Inferior Glenohumeral Ligament
With continuous high-velocity throwing:
• These ligaments tighten, stretch, or shift
• This leads to micro-instability and internal joint damage
From Tightness to Tears: The Spectrum of Pathology
Referencing the landmark research
“The Disabled Throwing Shoulder: Spectrum of Pathology”
by Dr. Stephen S. Burkhart, Dr. Craig D. Morgan, and Dr. W. Ben Kibler,
Dr. Londhe highlighted that:
• Simple posterior capsule tightness can snowball into major injury
• GIRD is directly linked to:
• SLAP tears
• Rotator cuff tears
• Labral injuries
• What starts as stiffness often ends in surgery if ignored
Rehabilitation Goals: Fix the Chain, Not Just the Pain
Dr. Londhe stressed that rehabilitation must go beyond local treatment. The primary goals include:
• Restoring internal rotation
• Strengthening the scapula and rotator cuff
• Improving core stability
• Emphasizing kinetic-chain-based rehabilitation
• Using:
• Proprioceptive training
• Plyometric exercises
• Functional movement retraining
“Without correcting the movement chain, pain relief alone is meaningless,” she noted.
The Pune Shoulder Rehabilitation Program: A Proven Model
The session also showcased the success of the Pune Shoulder Rehabilitation Program, which follows evidence-based kinetic-chain rehabilitation. Two athletes were cited as success stories:
• Ravi Kumar (Odisha)
• Dishant Patil (Maharashtra)
Both athletes suffered from throwing-related shoulder dysfunction and returned to sport successfully after structured GIRD-focused rehabilitation.
Key Takeaway from SSI Conclave 2025
Dr. Renu Londhe’s session made it clear that:
• GIRD is common, dangerous, and often overlooked
• Throwing injuries are not “just shoulder problems”
• Early detection, biomechanical correction, and kinetic-chain rehab can prevent career-threatening injuries
The session stood out as a powerful reminder that modern sports medicine is about movement science, not just pain management.
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