In a patient with glenohumeral joint effusion, which pattern of motion loss is MOST likely to occur?

• A. Maximal Loss of Lateral (External) Rotation, Moderate Loss of Abduction, Minimal Loss of Medial (Internal) Rotation
• B. Maximal Loss of Lateral (External) Rotation, Moderate Loss of Medial (Internal) Rotation, Minimal Loss of Abduction
• C. Maximal Loss of Medial (Internal) Rotation, Moderate Loss of Abduction, Minimal Loss of Lateral (External) Rotation
• D. Maximal Loss of Medial (Internal) Rotation, Moderate Loss of Lateral (External) Rotation, Minimal Loss of Abduction

Answer: (A)

When glenohumeral joint effusion is present, movement loss tends to follow a capsular-type pattern with external rotation most limited, followed by abduction, and internal rotation being the least affected. Swelling inside the joint increases intra-articular pressure and distends the capsule, especially impacting motions that require more posterior capsule stretch and joint surface contact. External rotation demands more posterior capsule and rotator cuff involvement, so it is the most restricted. Abduction still compresses the joint and is therefore moderately limited, while internal rotation requires less of the stretched capsule and is often least affected. This makes the pattern of maximal external rotation loss, moderate abduction loss, and minimal internal rotation loss the most consistent with a glenohumeral joint effusion.