Shoulder Throwing Injuries

Youth Shoulder Injuries/ Little Leaguer’s Shoulder

Youth throwing shoulders are still growing until the age of 18 when the growth plate of the humerus (arm bone) closes.  This is called skeletal maturity. The growth plate is made of cartilage, which creates new bone allowing the humerus to grow. This is an area of relative weakness. It has been shown there are adaptive changes that occur before skeletal maturity in thrower’s shoulders, which can result in a twisting or rotation of the ball (humeral head) in relation to the rest of the humerus. This results in greater external rotation (increased rotation behind the elbow in the cocking phase of throwing) and decreased internal rotation (less rotation down at ball release).

At times the stress on the growth plate is too great resulting in widening of the growth plate, which is known as epiphysiolysis or Little Leaguer’s Shoulder. This is probably the most common cause of shoulder pain in the preadolescent or adolescent baseball pitcher between 11-16 years of age and is related to throwing too hard, too much, or with bad mechanics. These are factors that can be modified by educating players, coaches, and parents. If players are having pain, they should stop throwing. It’s important to monitor pitch counts, obtain instruction on proper pitching mechanics, and emphasize core and lower body strengthening. Pitchers should not continue to throw when they develop pain as this could lead to worsening of this growth plate injury or cause an injury to the elbow due to altered pitching mechanics to avoid pain.

Widened growth plate

Normal Side

Dr. Khalfayan’s Tip!

I recommend that the player stop throwing when they feel pain. This includes throwing as a position player. A sports medicine specialist should evaluate the injury and X-rays obtained.

An MRI is not always needed. Treatment includes relative rest that allows activity other than throwing which does not cause pain. A course of physical therapy aimed at core and lower extremity strengthening followed by strengthening the shoulder blade and rotator cuff muscles is often helpful. An interval throwing program is started when there is no pain. I also recommend an assessment of pitching mechanics by a pitching coach to help avoid future injuries. These injuries may take up to 3 months to resolve.

Adult Shoulder Injuries

Injuries to the adult throwing shoulder usually involve the labrum (rim of cartilage around the socket) or rotator cuff. Labral tears are common in adult pitchers due to the forces placed on the throwing shoulder. Studies on pitchers where MRI scans were performed on shoulders without symptoms revealed a high percentage of abnormalities. This is in keeping with the finding that many pitchers with labral tears can continue pitching after a period of relative rest and rehabilitation. Although labral tears will not heal without surgery, many adult throwing shoulders can be treated nonoperatively.  If nonoperative treatment does not result in resolution of symptoms and allows a return to throwing, surgical repair is indicated (see sections on SLAP and Bankart Lesions).

Unstable SLAP Tear in right shoulder as seen from the back, top of the shoulder is to the left

Internal Impingement refers to impingement of the rotator cuff on the labrum and causes pain at the back of the shoulder.   This impingement occurs along the top and back part of the labrum and the infraspinatus tendon of the rotator cuff as the shoulder goes into the cocking position.  Over time this can result in fraying or a tear of the labrum and rotator cuff.  Treatment is usually rest and rehabilitation and if this is not successful, arthroscopic surgery may help.

Arthroscopic views of Internal Impingement in a pitcher’s shoulder

Partial Tear of the Rotator Cuff

Posterior Labral Fraying

 

GIRD or Glenohumeral Internal Rotation Deficit refers to loss of internal rotation of the shoulder due to a tight joint capsule in the back of the shoulder. This commonly responds to rehabilitation focused on sleeper stretches. Sleeper stretches are done by laying on the affected shoulder with the arm 90 degrees out in front of the body and rotating the forearm down.

 

Sleeper Stretch

Arthroscopic surgery to cut the tight joint capsule in the back of the shoulder may be needed for cases that do not respond to rehabilitation.  This is called a capsulotomy.

Rotator Cuff Tears can develop over time with pitching. These are usually partial thickness tears that involve a part of the tendon thickness and don’t go all the way through the tendon.  Occasionally, a tear of the rotator cuff may extend all the way through the tendon and this is called a full thickness tear. Return to play after surgical repair of rotator cuff tears in pitchers has a low success rate. That’s why the standard treatment for rotator cuff tears in adult pitchers is relative rest and rehabilitation while surgery is reserved for cases that don’t respond to nonoperative treatment. When surgery is performed for partial thickness tears in pitchers, it is usually an arthroscopic debridement.  Debridement is shaving frayed or damaged tissue as opposed to repairing it.