pathology: thrower’s shoulder

yogabook / pathologie / thrower’s shoulder

thrower’s shoulder / athlete’s shoulder

Definition of

The throwing movement consists of three phases (swinging, accelerating, decelerating), the last being the most critical because the exorotators have to eccentrically slow down the throwing movement, which also causes the posterior part of the capsule to be stressed and thickened as well the the inferior glenohumeral ligament to fibrose, thereby worsening endorotation ( GIRD : glenohumeral internal rotational deficit / glenohumeral internal rotation deficit ). This displaces the humeral head towards the end of the lunge phase and damages the biceps anchor and the rotator cuff. The GIRD should serve as a warning sign that impingement is developing . Various types of damage can occur to the shoulder:

  1. fraying Rotator cuff : partial tears, visible arthroscopically, for example as PASTA damage
  2. SLAP lesions
  3. Pulley-lesions
  4. Posterior labral lesions
  5. posterosuperiores Impingement (PSI)
  6. Damage to the posterior supraspinatus tendon or anterior infraspinatus tendon
  7. anterosuperior impingement (ASI), rare: the subscapularis tendon becomes trapped between the humeral head and the coracoid or anterior labrum )

Morgan describes the development of the disorder as follows:
It begins with weakness in the truncoscapular muscles , which stabilize the scapula , and weakness in the dorsal part of the rotator cuff . The inadequate guidance of the scapula is still painless, but a detectable GIRD occurs with a posterior inferior thickening of the capsule . As the contracture increases, the disorder becomes symptomatic, the pain becomes apparent in the late backswing phase and the early acceleration phase of the throw and is the result of the posteroinferior contracture, which pushes the in final exorotated frontal abduction the humus head superiorly (posteriorsuperior glenohumeral instability ). can The posterosuperior rotator cuff and the posterosuperior glenoid rim come into repeated contact, which to a SLAP lesion can lead . With continued practice of the sport of throwing, posterosuperior instability leads to narrowing of the subacromial space and additional external impingement and pain originating from the rotator cuff go out. In addition, the contracted posteroinferior capsule can lead to anterosuperior instability associated with a pathologically expanded exorotation ability due to the anterior subluxation of the humeral head .
An early warning symptom in the development of the pitcher’s shoulder is GIRD . If the disorder is advanced, the sport can no longer be practiced.

The case of a rotator tear with a partial tear of the lower surface of the infraspinatus tendonis called APIT (anteroposterior instability in the throwing athlete). The risk of injury in overhead sports without differentiation between acute traumatic and chronic degenerative: swimming (40-90%), volleyball and tennis (20-60%), baseball (60-70%). Forces of up to 1000 N occur during throwing. Changes in the shoulder can be detected after just 40-60 throws

Cause

  1. Repeated powerful overhead throwing and striking movement

Predisposing

  1. Enodorotation deficit (see GIRD test)

Diagnosis

  1. Rather loose connection between radiology and clinic
  2. Arthroscopy with measures depending on the damage
  3. Tests and signs: GIRD test (positive from 20° difference in side comparison), Fulcrum test, apprehension test in 120° lateral abduction, shoulder relocation test

Symptoms

  1. Movement pain, progressive, load-dependent, intra-articular
  2. Progressive terminal restriction of flexibility
  3. Slightly reduced retraction of the scapula
  4. Power reduction
  5. Scapular dyskinesia
  6. Subjective and objective joint instability

Complications

  1. Rotator tears
  2. Labrum damage
  3. SLAP lesion

Therapy

  1. if GIRD (glenohumeral internal rotational deficit) is recognized early: PT, adaptation of the throwing technique and other sports physiotherapy measures such as stretching of the pectoralis major, shoulder crossbody stretch (maximally transversely adduct the 90° frontally abducted arm), sleeper stretch (in lateral position with 90° frontal abduction of one arm, maximally endorotate this arm with the other hand)
  2. otherwise arthroscopic intervention is usually necessary. Good prognosis