The Postero-superior Contact and Rotator Cuff Lesion

The possibility of physiological contact between the deep surface of the tendon of the supraspinatus muscle and the labrum and/or posterior superior glenoidal rim during an armed movement of the arm (abduction and external rotation or ABER position) has been described for many years. The physiological hypotheses put forward to explain this contact are first of all that the intrinsic mobility of the scapulohumeral joint is limited by these 2 structures, that an anterior instability or micro-instability induces an abnormal anterior translation when performing an abduction and lateral rotation movement, or finally that there is a decrease in humeral retroversion. When this contact becomes symptomatic, it is called a posterior superior conflict. This pathology is mainly found in throwing athletes or athletes repeating maximum external rotation in the abducted position of the arm. This conflict is also described among some manual workers, and is then observed in an older age group.