•       The prevalence of  Glenohumeral internal rotation deficit in athletes playing overhead sports was found to be 29.1% (3)

•       The muscles of the rotator cuff have a crucial role in providing dynamic support at the shoulder joint, and an imbalance in the eccentric external rotation (ER) strength relative to the concentric internal rotation (IR) strength or a decrease in IR range of motion (ROM) in the dominant shoulder have been associated with shoulder pain in overhead athletes.

•       During bowling in cricket, the internal shoulder rotators are involved in the acceleration phase of the arm through concentric contractions, while the external rotators are involved during the deceleration phase.

•       The shoulder internal rotators (IR) contract concentrically to accelerate the arm as a cricketer releases the ball. The external rotators (ER) contract eccentrically to decelerate and regulate the speeding arm.(10)

•       Asymmetries in glenohumeral range of motion can lead to anatomical changes in the shoulder joint which can manifest as chronic shoulder pain. Assessment of range of motion may identify the shoulder joints functional restrictions and potentially could be used to predict injury risk. (9)

•       Rotator-cuff pathology in patients with GIRD can be separated into two categories: acute traumatic tears due to overload during deceleration (minority of tears), and partial- or full-thickness degenerative tears due to impingement.

·         The etiology of articular-sided tears is thought to be caused by a tight posterior capsule, leading to internal impingement, repetitive microtrauma, and shear stress on under-surface fibers, which have limited intrinsic repair potential.(12)

•       In throwers, the posterior capsule was found to be thicker in the dominant shoulder compared to the contralateral extremity.

•       Following simulated posteroinferior capsular tightness (with resultant GIRD), GH contact pressure and rotator-cuff impingement significantly increases.

•       translational changes in the humeral head occur, including increased superior displacement of the humeral head in maximum abduction and ER .These shifts in humeral head center of rotation have implications for injury, due to altered joint kinematics. (12)