What characterizes the sulcus sign in a shoulder exam?

The sulcus sign is characterized by a palpable dip just below the acromion. This sign is indicative of inferior shoulder instability, often associated with conditions like multidirectional instability or a glenohumeral joint issue. When the arm is pulled downward, a depression or "sulcus" can be felt beneath the acromion due to the head of the humerus moving inferiorly.

This finding is particularly pertinent during a physical examination of the shoulder, as it helps assess the integrity of the shoulder joint and the surrounding soft tissues. The presence of this sign signals the potential for instability and guides further evaluation or intervention.

In contrast, other options do not accurately represent the characteristics of the sulcus sign. Severe pain during range of motion relates more to acute inflammatory conditions or rotator cuff injuries rather than a specific sign of instability. Swelling of the acromion may indicate acute trauma or inflammation but does not pertain to the sulcus sign. Increased shoulder abduction strength is not typically associated with this sign, as weakness or instability can be present in cases demonstrating a sulcus sign.