Three-dimensional glenohumeral arthrokinematics related to internal impingement in throwing athletes : communication on six clinical casesThree-dimensional glenohumeral arthrokinematics related to internal impingement in throwing athletes : communication on six clinical cases
Faculty of Medicine and Health Sciences
Antwerp Surgical Training, Anatomy and Research Centre (ASTARC)
European journal of sport science
10(2010):6, p. 427-433
University of Antwerp
The aim of this study was to undertake a comparative arthrokinematic evaluation of the shoulder of throwers with internal impingement. The participants were six throwing athletes with internal impingement type I. The intra-articular position of the humeral head on the glenoid in the apprehension test pose was evaluated using three-dimensional reconstructions obtained on medical images. Glenohumeral internal rotation deficit, external rotation gain, and the difference in posterior shoulder tightness were assessed goniometrically. No abnormal translation behaviour of the humeral head on the glenoid could be demonstrated, with a posterior positioning of the humeral head in relation to the centre of the glenoid of -6.6±0.9 mm and a superior positioning of +2.3±1.5 mm, despite the presence of a glenohumeral internal rotation deficit between the throwing shoulder and the contralateral shoulder of -26.3±7.2° and a difference in posterior shoulder tightness of -6.7±2.9 cm. In conclusion, the results do not support the biomechanically based hypotheses relating internal impingement at the end of the late preparatory phase of throwing with an increased posterior-superior or anterior-inferior glenohumeral translation. Instead, the results favour a physiological cause of symptomatic internal impingement.