Push-ups are foundational for developing the chest, triceps, and anterior shoulders. However, the movement also requires contribution from smaller, deeper muscles that ensure joint stability and proper mechanics. One such muscle is the serratus anterior, a frequently overlooked player in the pushing motion. Understanding how this muscle functions helps clarify its role and how its activation can be maximized for better upper body health and strength.
The Serratus Anterior: Function and Importance
The serratus anterior is a broad, fan-shaped muscle located on the side of the chest wall. It originates on the upper ribs and wraps around the rib cage to insert along the medial border of the scapula (shoulder blade). Its primary function is to pull the scapula forward and around the rib cage, a movement known as protraction.
This muscle is often called the “boxer’s muscle” due to its power in driving the arm forward during a punch. The serratus anterior is responsible for holding the scapula firmly against the thoracic wall. When this muscle is weak, the inner border of the shoulder blade can protrude away from the ribs, a condition called “scapular winging.”
Maintaining scapular stability is important for all overhead and pressing activities. It works with the trapezius muscle to facilitate the upward rotation of the shoulder blade, which is necessary to safely elevate the arm above the head. Without its proper function, the mechanical efficiency of the entire shoulder girdle is compromised.
How Standard Push-Ups Engage the Serratus Anterior
A standard push-up is a closed-chain exercise where the hands are fixed on the ground. During the lowering phase, the scapulae naturally retract toward the spine. The serratus anterior acts eccentrically, controlling this movement and resisting excessive inward collapse of the shoulder blades.
The greatest activation occurs during the concentric, or pushing, phase, especially as the arms approach full extension. While the pectoralis major and triceps brachii are the prime movers, the serratus anterior finishes the motion. This final phase involves protracting the scapula to achieve a full lockout.
Electromyography (EMG) studies confirm the serratus anterior is highly active during a push-up. It ensures the shoulder socket is stable against the rib cage, allowing the chest and arm muscles to exert force safely. Without this stabilizing and protracting action, the final few degrees of extension are mechanically incomplete, leading to poorly distributed forces on the shoulder joint.
Technique Adjustments for Maximum Activation
To increase activation of the serratus anterior during the push-up, a specific modification known as the “Push-Up Plus” is used. This technique builds upon the standard push-up by adding a distinct protraction movement at the top of the repetition. After completing the standard push-up and fully extending the elbows, the movement continues by actively pushing the hands into the floor.
This action involves rounding the upper back slightly and pushing the torso away from the ground. The key to this technique is that the elbows must remain straight throughout the “plus” portion of the movement. The entire motion is driven solely by the muscles controlling the scapula, particularly the serratus anterior.
When performing the Push-Up Plus, focus on the cue of “pushing your back toward the ceiling” rather than shrugging the shoulders toward the ears. Shrugging primarily engages the upper trapezius, which reduces the serratus anterior’s workload. EMG analysis has shown that the Push-Up Plus maximizes serratus anterior activity while minimizing the involvement of the upper trapezius.
A common error that reduces serratus anterior involvement is allowing the shoulder blades to collapse inward at the top of the push-up range. The Push-Up Plus ensures the serratus anterior is fully recruited to stabilize and drive the shoulder girdle. This intentional modification transforms the push-up into a powerful tool for developing scapular control and stability.