CAMRT Radiography Practice Exam

What structure is prominently displayed in profile laterally with external rotation of the humerus?

1. Less tubercle

2. Greater tubercle

3. Coracoid process

4. Surgical neck

The correct answer is: Greater tubercle

The structure that is prominently displayed in profile laterally with external rotation of the humerus is the greater tubercle. When the arm is externally rotated, the positioning allows the greater tubercle to be fully visible on the lateral side of the humerus. This anatomical landmark serves as an important attachment site for the rotator cuff muscles, particularly the supraspinatus, infraspinatus, and teres minor. In contrast, while the lesser tubercle, coracoid process, and surgical neck are also parts of the shoulder anatomy, they do not come into view in the same manner with external rotation. The lesser tubercle is more medial and typically not as prominent on a lateral view. The coracoid process, arising from the scapula, is situated more anteriorly and would not typically be highlighted in a lateral view. The surgical neck of the humerus is also not easily distinguished in profile during this specific rotation, as it is located more inferiorly. The prominence of the greater tubercle in this position is critical for assessing the shoulder joint and its associated structures during imaging.