Which pair of muscles are the largest in terms of surface area?

The latissimus dorsi (/ləˈtɪsɪməs ˈdɔːrsaɪ/) is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline.

The pair of muscles are commonly known as "lats", especially among bodybuilders.

The body's largest muscle by mass is the gluteus maximus, but the two latissimus dorsi are the largest in terms of surface area.

The latissimus dorsi is responsible for extension, adduction, transverse extension also known as horizontal abduction (or horizontal extension), flexion from an extended position, and (medial) internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine.