The lats are the largest muscle in the upper body and the widest muscle in the entire body. The traps consists of three muscles: lower, middle and upper trapezius. They are mostly involved in shrugging and rowing exercises. The rear delt, is basically a part of the deltoid muscle. Nevertheless I’ve listed it here too, as you can see it from the back. The rhomboids are two muscles (rhomboid major and minor) located between the shoulder blades and spinal column.
