Which of the following muscles produce upward scapular rotation when the shoulder girdle is elevated from 90 ° to 180 °?

a. Deltoid and rotator cuff muscles
b. Upper trapezius, lower trapezius, and serratus anterior
c. Upper trapezius and serratus anterior
d. Teres major and teres minor

ANS: B
This force couple is indicated as the primary muscles that contribute to upward rotation of the scapula. The muscles play various roles during different points of shoulder girdle elevation, but all contribute to full upward rotation of the scapula.