What type of muscle activity characterizes the serratus anterior during a push-up with scapular protraction?

• A. Concentric contraction
• B. Eccentric contraction
• C. Isometric contraction
• D. Static contraction

Answer: (A)

During a push-up with scapular protraction, the serratus anterior muscle engages primarily in concentric contraction. This muscle is responsible for the protraction and stabilization of the scapula against the thorax as the arms are pushed away from the ground.

In concentric contraction, the muscle shortens while generating force. As the individual pushes their body upward, the serratus anterior contracts to pull the scapula forward around the ribcage, enabling effective arm movement and contributing to the overall strength and stability of the shoulder girdle. This is essential for facilitating the pushing motion of the push-up, as the movement requires both strength and coordination in the core and upper body.

Other types of contractions, such as eccentric contraction, would involve the muscle lengthening while still being under tension, which is not the case in this particular movement phase. Isometric contraction refers to tension being generated without any change in muscle length, which also does not accurately describe the serratus anterior's role during the push-up. Static contraction is often used interchangeably with isometric contraction and similarly does not apply here. Thus, the concentric activity of the serratus anterior in this context is crucial for the successful execution of the push-up with scapular protraction.