WEBVTT 00:00:00.000 --> 00:00:02.000 (English captions by Andrea Matsumoto from the University of Michigan) 00:00:02.760 --> 00:00:07.319 To test inferior glenohumeral stability place traction on the humerus with the arm at the 00:00:07.319 --> 00:00:08.230 patient's side. 00:00:08.230 --> 00:00:12.970 If a gap greater than 1cm appears between the humoral head and the undersurface of the 00:00:12.970 --> 00:00:17.489 acromion it is considered a positive sulcus sign with inferior instability.