A cable crossover is proficient at building strength and muscle in the upper body. The crossover movement is performed on a double-stack cable column. The cable crossover can be performed seated, but is most effective in a standing position. When doing cable crossovers, keep a full split position in your legs for a stable base of support. Bring the cable handles through a wide, angular motion to maximize chest and core recruitment. Prevent excessive backward movement of the cable handles, which puts tremendous stress on the shoulder and elbow joints.
The pectoralis major or chest is the principal muscle recruited during a cable crossover. The joint action for the pectoralis major is horizontal adduction, an angular motion toward the mid-line. Your chest contraction is what allows the cable handles to "cross" toward the middle of the body. A cable crossover works the pecs better than a barbell or chest press machine. A barbell or machine has a fixed path of motion, which doesn't allow a horizontal angular motion. A cable apparatus permits a free path of motion, letting the arms move openly through the center.
The cable crossover requires the anterior and posterior regions of the shoulder girdle to carry out two specific functions. The anterior deltoid, which flexes the shoulder, initiates the concentric phase of the movement. The concentric phase is when your muscle shortens under tension. Your arms start the exercise by holding the cable handles at a right angle. Your shoulders flex to move the cable handles from their stationery position. The anterior or front of your shoulder engages to produce a constant muscular force.
The middle/lower trapezius are key to decelerating the cable resistance during the eccentric phase. The eccentric phase is when the muscle lengthens to control tension. The traps are what allow your hands to widen to get the arms back to a right angle. They also prevent shoulder strain and produce a momentary pause between the eccentric and concentric phases of motion.
Your core is immediately involved the moment you engage the cables since the torso needs to be stabilized against the opposing torque. The core has to stay engaged throughout the exercise in order for the movement to stay isolated to the chest and not involve other muscles through "cheating".