Fig. 2

Motion of an asymptomatic volunteer. The left shoulder of a participant. The movement of the subscapularis and infraspinatus muscles of an asymptomatic shoulder was clearly visible using cine-MRI and no blurring was observed. 1, Starting position; 2, Motion in external rotation; 3, Point at the maximum external rotation; 4 and 5, Motion in internal rotation; 6, End position. *, The lesser tuberosity of the humeral head; #, The subscapularis; †, Glenoid; ○, The infraspinatus; △, The deltoid