Shoulder Blades and Lat Pull-Downs

The lat pull-down works your latissimus dorsi -- the largest muscle in the back. The muscle pulls your upper arms down toward your torso as you pull the overhead bar down to your upper chest. While the shoulders are where the primary movement is occurring during a lat pull-down, the activity is considered a compound exercise because it involves movement at multiple joints, including your shoulder blades.

  1. Shoulder Blades

    • Your shoulder blades, or scapula bones, are located in your upper back and connect your upper arm bone with your clavicle. As you move your upper arms around, your scapula joints move as well. The muscles that control your shoulder and scapula joints coordinate when you move your upper arm, such as when you pull your arms down during a lat pull-down. The lat pull-down is effective at developing the back and improving scapular stability, which in turn helps you maintain proper posture and spinal alignment.

    Scapular Downward Rotation

    • Scapular downward rotation occurs when your two scapula bones rotate, with the bottom tip of each bone moving inward and downward toward the spine, and the top of each bone moving outward away from the spine. The collection of muscles that handle this include your levator scapulae, rhomboids, pectoralis minor and latissimus dorsi.

    Scapular Adduction

    • When you pull the overhead bar down, your scapulae are also simultaneously adducting, which means that the inside edge of each of the bones are pinching together toward the spine. The muscles responsible for scapular adduction, commonly referred to as retraction, include the middle and lower sections of your trapezius, your rhomboids -- located in between the scapular bones -- and the latissimus dorsi.

    Effect of Grip Variations

    • How you grip the bar will make a difference in the movement of your scapulae. The wider the grip, the more your shoulders are moving toward the sides of your torso as you pull the bar down; there is more scapular downward rotation and less adduction. If you bring your grip in to a more narrow position, your scapulae will move with a greater degree of adduction.