BACK: The back is built of a massive web of muscles, so to keep this focused, we’ll only go over the largest back muscles.
Trapezius (Traps)
Training Movements: T-bar row, Cable seated row, deadlift, dumbbell row, hex bar, pendlay row, reverse pec deck, seated face pull.
The trapezius aka traps is a large muscle running from the base of the skull down to the middle of your inner back. Usually, when people think about the traps, they tend to only think of the upper muscle, but the middle and lower fibers take up a pretty large area as well.
The traps work to elevate the scapulae (shrugging your shoulders), retract the scapulae (pull the shoulder blades back), and extend the shoulder (pull your arms backward when your elbows are raised).
ORIGIN: Occipital bone (upper traps), corresponding supraspinous ligaments for the mid and lower traps
INSERTION: Nuchal ligament
Latissimus dorsi (Lats)
Training Movements: Cable-pullover, chin-up, pronated pulldown, and weighted pull-up
Latissimus dorsi aka Lats is a big muscle that runs from underneath your armpit all the way down to the bottom of your back. The lats primarily act to extend the shoulder (bring your upper arm downward) and adduct the shoulder (moving your elbows towards your mid-back).
ORIGIN: Illiac crest and thoracolumnar fascia
INSERTION: Humerus