The spring chest expander is an old-school piece of exercise equipment that engages your shoulders, chest, upper back and core, through resistance movements. This exercise apparatus traces its origins to England with a popularity boom by English gentlemen at the turn of the 20th century. The spring chest expander is made up of three to five strands of steel springs or rubber cables that run together with handles on each end. Strongman cables, pulls or strand pulls are nicknames often given to the chest expander.
The spring chest expander works the deltoids as the primary muscle for the movement. There are three primary sections to your deltoids, or shoulder muscles, anterior or front, middle and posterior or back. The main movement of the spring chest expander is a pulling movement that requires muscle activation from all parts of the shoulder. To effectively engage the shoulders without stress with the basic move, keep your shoulders down away from your ears and always hold the equipment at shoulder level while pulling.
You engage the pectorals, or chest muscles, as your secondary muscles when working out with this equipment. The basic expansion move, which holds the spring chest expander at shoulder level in front of your chest and pulls outward, requires chest strength to help the shoulders. The upper part of the chest engages as you draw the cables outward, creating chest flexion. To engage the chest even more, utilize the resistance of the release by flexing the chest as the cables return back to the center. Make sure you release back to your starting position slowly and visualize squeezing the chest inward.
The basic exercise of the spring chest expander also engages the upper back muscles. The pulling action requires the upper back to engage. To get more back flexion out of this exercise, squeeze your shoulder blades toward each other as you pull the chest expander outward.
Core and Posture
As you stand and execute the basic exercise, keep your torso upright and visualize engaging your entire core. The more you involve your core during the exercise the easier it will be to isolate the upper body. Working your shoulders, chest, back and core with this one exercise will help keep your posture in correct alignment.