Answer: Serratus anterior abducts the scapula and rhomboids adducts the scapula.
Serratus anterior is a muscle that originates of the 1st to 8th ribs at
the side of the thorax and inserts in
the medial border of the scapula. This muscle during contraction abducts the scapula and the rhomboids muscles do the opposite by retracting the scapula toward the vertebral column(adducts).