Which muscles act as antagonists to adduction of the scapula?

• A. Trapezius (Upper), Levator Scapulae
• B. Rhomboids, Levator Scapulae
• C. Pectoralis Minor, Serratus Anterior
• D. Serratus Anterior, Pectoralis Minor

Answer: (D)

Adduction of the scapula is scapular retraction—pulling the shoulder blades toward the spine. The muscles that pull the scapula forward and away from the spine (protract the scapula) are the ones that oppose this action. Serratus anterior and pectoralis minor are the primary protractors: serratus anterior pulls the medial border of the scapula forward against the rib cage, while pectoralis minor tips and protracts the scapula by drawing the coracoid area forward with respect to the ribs.

So, the pair that best opposes adduction is the combination of serratus anterior and pectoralis minor. The other options include muscles that retract or elevate the scapula, which would not oppose adduction.