GLENOHUMERAL INTERNAL ROTATION DEFICIT
Matt Holland, PT
The throwing shoulder must be mobile enough to allow the extremes of external rotation needed to throw a ball, but it is a delicate balance between mobility and stability that is needed to perform the demands of the overhead throwing motion without undue strain on the other structures of the shoulder joint.
Increased external rotation with a loss of internal rotation ROM is a natural adaptation in the thrower’s shoulder. Multiple theories exist as to how the adaptations occur including changes in humeral retroversion and repetitive microtrauma to the posterior capsule leading to thickening and contracture of the posture capsule of the shoulder. When this loss of internal rotation exceeds 20-25 degrees from the non throwing side excessive strain on the structures of the shoulder may result in further problems and shoulder pathology including superior labral tears (SLAP tears), biceps tendonitis, rotator cuff tendonitis or tears, and pain with throwing will occur. When the arm is in the cocked position the posterior capsule moves under the humeral head and if the posterior capsule is too tight it is like a hammock that is strung too tight pushing the humeral head upward and resulting in increased strain and shear on the labrum, rotator cuff, and biceps tendon. As the shoulder moves from a cocked position forward during acceleration this posterior capsule tightness creates increased shear that will damage these structures over time.
For many years we have worked diligently on stretching the posterior capsule to improve internal rotation ROM and decrease pain and injury in the thrower’s shoulder. We have primarily focused on stretching internal rotation with the “Sleeper’s Stretch” position. Recently in following up with these athletes we have noticed that their internal ROM in abduction at 90 degrees improves, but many are still exhibiting tightness of the posterior shoulder into horizontal adduction across the body. Therefore we have begun to focus not only on internal rotation stretching with the Sleeper stretch, but also working on cross body adduction. Having good flexibility and ROM across the body is of particular importance during the follow through phase of throwing.
Studies show that approximately 90 percent of all athletes with GIRD will gain ROM in internal rotation when they are enrolled in a consistent program focusing on the posterior capsule.
Capsular stretching should be done consistently and it is important to remember that the capsule is best stretched with a low load and prolonged duration of stretching and done on a daily basis. It is also important for the therapist, coach, and athletic trainer to remind the athlete that the capsule is highly innervated and overstretching of the capsule will result in a great deal of pain. Resolving IR deficits often happens very quickly and will result in substantial reduction of pain with throwing. It is critical for the athlete to maintain ROM and be consistent and compliant with the internal rotation stretching program throughout the season.
Below is our protocol for internal rotation stretching.
3 sets of 15-30 sec holds
SIDE LYING CROSS BODY ADDUCTION
3 sets of 15-30 sec holds
Laying on affected side to block scapular motion
Use unaffected side to prevent arm from drifting into external rotation
Make sure athlete stays rolled toward the affected side to prevent compensation
For shoulders that are more difficult to gain ROM the therapist and athletic trainer can use the following manual therapy techniques to gain ROM. Perform manual techniques at least 3 times per week.
MANUAL PASSIVE IR STRETCHING
Posterior capsule mob with the arm in external rotation (remember in external rotation the posterior capsule is inferior to the humeral head) Direction of mobilization: inferior and posterior
SUPINE CROSS BODY ADDUCTION WITH THE SCAPULA BLOCKED
Scapula can be blocked with one hand or one hand on each scap to hold the athletes body still. Athlete then pulls arm across the body using the nonthrowing elbow on top of the throwing hand to prevent the arm from drifting into external rotation. As an alternative, the therapist can stabilize the scapula while pushing the arm across body. They key is to keep the forearm parallel to the shoulders. The shoulder will try to rotate externally as you push cross body. Check the video.
PRONE INTERNAL ROTATION STRETCHING WITH THE SCAPULA BLOCKED.
Use one of your hands to hold the scap down and then gently using your forearm push the athletes elbow toward the floor. CAUTION: THIS IS AN AGGRESSIVE STRETCH AND YOU WILL ONLY NEED MINIMAL FORCE. LET OFF SLOWLY OR THE ATHLETE WILL HAVE A GREAT DEAL OF PAIN!