78 overhead athletes with Glenohumeral Internal Rotation Deficit (GIRD) will be included in this study. Participants will be randomly divided into 3 different groups of 26 people. In each group will be applied posterior shoulder stretching exercises (PSSE) performed with different Muscle Energy Techniques (MET).

Post Isometric Relaxation Group (PIRG) participants will perform a PSSE with post isometric relaxation (PIR) technique, Isolytic Stretching Group (ISG) participants will perform a a PSSE with isolytic stretching technique and Static Stretching Group Group (SSG) participants will perform a PSSE with static stretching technique. All exercises will be performed in the modified crossbody position, for 5 times a week total of 6 weeks. Subacromial space, posterior capsule and muscle tendon thicknesses will be measured using a 7-12 MHz linear transducer with USG (LOGIQ e Ultrasound, GE Healthcare, USA). Athletes' GIRD results and rotational ROM measurements and Posterior shoulder tightness will be measured and recorded using a bubble inclinometer (Fabrication End Inc, New York, USA). Scapula kinematics (posterior tilt, upward rotation) will be evaluated with a digital inclinometer. Shoulder and scapular muscles will be evaluated with hend held dynamometer. Tightness of Levator scapulae and pectoralis minor will be assessed. The upper extremity functional performance of the athletes will be evaluated with the Functional Throwing Performance Index (FTPI). Evaluations will be performed before training program and repeated after 6 weeks of training, and at the 1st, 3th and 6th months after training program is completed and the effects of different muscle energy techniques (MET) will be compared. Investigators hypothesized 6 weeks of PSSE with different MET would have different effects on Acromio-Humeral Distance, posterior capsule thickness, muscle tendon thickness, rotational ROM measurements, scapula kinematics, muscle strength, posterior shoulder tightness and performance on overhead athletes with GIRD and the effects of MET would be superior to static stretching.

Inclusion Criteria:

• Being overhead athlete
• Glenohumeral internal rotation range of motion of the affected shoulder should be less than other shoulder and bilateral shoulder internal rotation range of motion difference should be ≥15 º

Exclusion Criteria:

• Shoulder pain required medical attention for the last year.
• Current shoulder pain
• Cervical pain during upper extremity movement
• History of fracture to the shoulder girdle
• Systemic musculoskeletal disease
• History of shoulder surgery,
• Glenohumeral instability (positive apprehension, relocation, or positive sulcus test) or positive findings for a full thickness rotator cuff tear (positive lag sign, positive drop arm test, or marked weakness with shoulder external rotation)