Fig. 15.

Axial dynamic ultrasound images during progressive internal rotation of the shoulder (from a to d). Anatomic landmarks are the coracoid process (white arrow head), the lesser tuberosity (black arrow heads) and the intertubercular sulcus (black arrow). A macrocalcification is seen in the SSC tendon (arrow). It gradually approaches the coracoid process (b and c). In internal rotation (d), pain and sensation of projection under the probe when calcification passes under the coracoid process, are consistent with coracoid impingement (lightning) associated with calcific tendinitis