What are Throwing Injuries in the Shoulder?
Overhead throwing athletes can sustain injuries in the shoulder due to repetitive overhand motions and trauma during sporting activities. Commonly, this occurs in baseball athletes but can occur in other sports such as volleyball, tennis, swimmers, and certain track and field events. These athletes produce high stresses to the shoulder with repetitive motions which can lead to overuse injuries.
Anatomy
The shoulder is a ball-and-socket joint which consists of the humerus (upper arm bone), the scapula (shoulder blade), and the clavicle (collarbone). The ball of the humerus fits into the socket of the shoulder blade, called the glenoid. A labrum is a fibrous tissue ring that surrounds the socket and allows the ball to sit deeper in the shoulder joint. The labrum plays a roll in the stability of the shoulder and serves as an attachment to the ligaments in the shoulder and the biceps tendon.
The shoulder capsule is a strong connective tissue that surrounds the entire shoulder joint and helps keep the ball in the socket.
There are multiple tendons and muscles that surround the shoulder joint to keep the shoulder stable and give you the ability to have strength lifting overhead. The rotator cuff tendons are a group of four muscles that form a cuff or covering over the humeral head. The biceps muscle has two attachments in the shoulder. The long head of the biceps muscle attaches within the shoulder joint to the labrum and often causes issues in overhead throwing athletes.
Causes of Throwing Injuries in the Shoulder
This is due to the repetitive high stress that is placed on the shoulder anatomy with overhead throwing maneuvers. This can result in a wide range of injuries involving ligaments, muscles, tendons, and cartilage.
Common Throwing Injuries in the Shoulder
SLAP tears: This is a tear in the superior labrum and extends from the front to the back parts of the labrum. Commonly, this causes pain deep in the shoulder with certain arm positions and can cause locking and popping.
Instability: Shoulder instability occurs when the ball comes out of the socket (dislocation). This can cause the capsule in the shoulder to loosen overtime and result in recurrent or chronic instability of the shoulder. Overhead throwing athletes will develop loosening of the shoulder joint over several years. If this looseness or laxity becomes too great, then the muscles of the shoulder joint cannot hold the ball in the socket, resulting in slipping of the shoulder joint.
Biceps tendonitis/tears: The long head of the biceps tendon attaches to the superior labrum in the shoulder and often becomes inflamed or irritated with overhead throwing athletes. This causes pain in the front of the shoulder and can tear over time.
Rotator Cuff Tendonitis/Tears: The rotator cuff group of muscles can become inflamed with repetitive overhead throwing motions. This can result in pain down the side of the shoulder. As symptoms progress, the athlete may lose motion in the shoulder and strength. Rotator cuff tendon tears can occur as symptoms progress.
Impingement: Overhead throwing athletes place their shoulder in extreme positions which can cause the rotator cuff tendons to be pinched in the back of the shoulder. This is called internal impingement and can result in significant discomfort, especially in the late cocking phases of throwing.
Glenohumeral Internal Rotation Deficit (GIRD): Throwers usually gain their velocity or speed of throwing due to their extreme external rotation of their shoulder. This results in tightening of the back of the shoulder which causes loss of internal rotation. Ultimately, this will increase the risk of labral and rotator cuff tears.
Scapular Rotation Dysfunction (SICK Scapula): For the shoulder to function properly, the scapula or shoulder blade needs to move in precision with the shoulder joint. There are several muscles surrounding the shoulder blade that coordinate this movement. During overuse injuries, the muscles surrounding the shoulder can become affected and increase the risk of injury to the shoulder.
Diagnosis of Shoulder Throwing Injuries
A history and physical exam by a qualified shoulder specialist will often focus on the duration of symptoms and any specific events that caused the shoulder injury. The exam will check range of motion, strength, and stability of the shoulder. X-rays of the shoulder are necessary to see the anatomic bony appearance of the shoulder. Advanced imaging with MRI, CT or Ultrasound can be performed to further delineate the problems in the shoulder.
Treatment
Non-operative management is often first attempted in any overhead throwing athlete. This will involve rest, anti-inflammatories, ice, and physical therapy. PT will work on regaining range of motion of the shoulder, stretching, and strengthening of the surrounding shoulder muscles. Working on throwing mechanics with a pitching coach or athletic trainer can be helpful. Injections (PRP and cortisone) can be used to help decrease the pain and inflammation in the shoulder.
Surgical management can be pursued if conservative treatment measures have failed. This can involve arthroscopic or open surgery. Most throwing injuries can be treated with arthroscopic surgery. This involves using a small camera and small surgical instruments through poke hole incisions to perform the surgery. In rare cases, open surgical treatment of shoulder problems may be recommended. PT after surgery is required to work on the shoulder while not damaging the repair. The rehabilitation often takes several months to complete and will end with a gradual return to sport.
For more information, please consider the following link that was produced by the AAOS.