<prompt> The most important physical sign for the diagnosis of anterior instability of the glenohumeral joint is a positive:Apprehension signImpingement signResisted straight arm raising signResisted forearm supination sign  <response>: Ans. A. Apprehension signClassically, a patient with recurrent anterior instability or subluxation exhibits marked apprehension when the relaxed shoulder is stressed in abduction and external rotation. The impingement sign and the drop arm sign indicate disease of the rotator cuff. A positive resisted straight arm raising test Speeds test and a positive resisted forearm supination test Yergasons sign suggest pathology in the biceps tendon. 