Dips are compound bodyweight exercises performed on parallel bars. The serratus anterior, often called the “boxer’s muscle,” is located on the side of the rib cage and supports shoulder health and movement. Whether the standard dip effectively engages this muscle is a frequent topic of discussion. The answer lies in understanding the specific biomechanics of the movement.
Anatomy and Function of the Serratus Anterior
The serratus anterior is a large, fan-shaped muscle that originates from the outer surfaces of the first eight or nine ribs at the side of the chest wall. It wraps around the rib cage and inserts along the medial border of the scapula (shoulder blade). This attachment means the muscle lies primarily beneath the scapula and the other chest muscles.
Its primary function is scapular protraction, pulling the shoulder blade forward and around the thorax, similar to throwing a punch. The muscle also aids in the upward rotation of the scapula, necessary for lifting the arm overhead. The serratus anterior acts as a dynamic stabilizer, pressing the shoulder blade against the rib cage to prevent “scapular winging.”
Primary Muscle Engagement During Dips
The standard parallel bar dip is a multi-joint pressing exercise that heavily recruits the anterior upper body musculature. The primary muscles responsible are the pectoralis major (lower chest) and the triceps brachii. These muscles extend the elbow and perform shoulder adduction as the body is pressed upward from the bottom position.
The anterior deltoids also contribute significantly to the pressing action. The rhomboids and middle trapezius muscles in the upper back stabilize the shoulder blades, ensuring a stable platform. The serratus anterior is considered a secondary muscle, acting as a stabilizer rather than a main force producer.
How Dips Engage the Serratus Anterior
The serratus anterior is engaged in the dip, but its role is primarily stabilizing, not propulsive, during the pressing phase. As the body descends, the shoulder blades naturally retract and slightly elevate. The serratus anterior controls this retraction and maintains the scapula’s position against the rib cage, resisting the body’s weight.
Activation is highest at the deepest point of the dip and as the lifter begins the upward press. The muscle acts as a dynamic brake, preventing excessive scapular retraction and minimizing injury risk to the shoulder joint. Without this stabilizing function, the shoulder joint would be less secure under the load. The serratus anterior receives a significant isometric and stabilizing workout even during a standard dip.
Technique Adjustments for Targeting the SA
While the standard dip engages the serratus anterior for stability, the exercise can be modified to maximize its involvement. The key adjustment shifts the focus from elbow extension and chest pressing to scapular protraction. This variation is often referred to as a “serratus dip” or “dip shrug.”
To perform this, the arms must remain straight and locked out at the top of the dip station. Instead of bending the elbows, the user allows the body to sag down, letting the shoulders elevate and the shoulder blades retract. The movement is completed by forcefully pushing the body upward by protracting the shoulder blades—pushing them forward—without bending the elbows.
A refinement involves incorporating a slight forward hunch or rounding of the upper back at the peak of the upward movement. This “plus” movement emphasizes the final range of motion for scapular protraction. By focusing on this controlled, limited scapular motion while keeping the triceps and chest static, the exercise becomes a more direct way to train the serratus anterior.