During the throwing motion high forces are placed on the athlete's
shoulder and extreme positions of external rotation and abduction
are reached. The dynamic and static stabilizers of the glenohumeral
joint need to handle a delicate balance between shoulder mobility
CAUSES OF INJURY
Repetitive forces lead to adaptive osseous, capsular, ligament and
muscular changes. This should increase external rotation of the
shoulder and thus initially help to improve performance but
ultimately could cause shoulder pathologies. For instance, tissue
overuse can result in muscular imbalance, functional instability and
posterior capsular contracture with the development of a
glenohumeral internal rotation deficit.
An internal impingement is often observed in throwing athletes which
can be subdivided into the more common posterosuperior type and the
rarer anterosuperior type. Typical lesions in the throwing shoulder
are articular-sided partial rotator cuff tears, labrum and biceps
tendon lesions and edema, cysts or osteochondral lesions of the
humeral head or glenoid.
For an accurate diagnosis it is important to include the history, a
thorough physical examination and magnetic resonance arthrography.
The correlation of clinical examination and imaging is critical to
identify symptomatic lesions.
If conservative therapy fails or in cases of significant structural
damage resulting in clinical symptoms, surgical treatment should be
considered based on the underlying pathology and carried out using
established techniques and criteria.