Walch et al. describe a distinct impingement mechanism in 17 overhead athletes with unexplained throwing-related shoulder pain and no anterior instability. The study asks whether contact between the deep cuff surface and the posterosuperior glenoid rim in the throwing position can explain rotator cuff and labral pathology unaccounted for by Neer's outlet impingement or Jobe's instability model. All 17 patients were examined arthroscopically with the arm in 90° abduction and full external rotation.
When a young overhead athlete presents with posterior shoulder pain in the late cocking position, a positive relocation sign, and no apprehension or instability — the diagnosis is posterosuperior glenoid impingement until proven otherwise.
This paper is why we do not stop at arthrography in throwers. Nine of 17 patients had cuff tears invisible on arthrogram; only arthroscopic examination in the throwing position revealed the full extent of disease.
The relocation test is positive in these patients not because you are reducing anterior subluxation, but because you are pushing the humeral head posteriorly away from the glenoid rim. Understanding this distinction prevents misclassifying posterosuperior impingement as instability-driven disease.
Anterior acromioplasty, the standard treatment for Neer impingement, fails in this population. Tibone et al. Showed only 22% of throwers returned to sport after acromioplasty, and Walch's anatomic framework explains why: the pathology is on the articular side, not under the acromion.
Walch et al. describe a distinct impingement mechanism in 17 overhead athletes with unexplained throwing-related shoulder pain and no anterior instability. The study asks whether contact between the deep cuff surface and the posterosuperior glenoid rim in the throwing position can explain rotator cuff and labral pathology unaccounted for by Neer's outlet impingement or Jobe's instability model. All 17 patients were examined arthroscopically with the arm in 90° abduction and full external rotation.
When a young overhead athlete presents with posterior shoulder pain in the late cocking position, a positive relocation sign, and no apprehension or instability — the diagnosis is posterosuperior glenoid impingement until proven otherwise.
This paper is why we do not stop at arthrography in throwers. Nine of 17 patients had cuff tears invisible on arthrogram; only arthroscopic examination in the throwing position revealed the full extent of disease.
The relocation test is positive in these patients not because you are reducing anterior subluxation, but because you are pushing the humeral head posteriorly away from the glenoid rim. Understanding this distinction prevents misclassifying posterosuperior impingement as instability-driven disease.
Anterior acromioplasty, the standard treatment for Neer impingement, fails in this population. Tibone et al. Showed only 22% of throwers returned to sport after acromioplasty, and Walch's anatomic framework explains why: the pathology is on the articular side, not under the acromion.