Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Start in a high plank. Maintain a straight line from head to heels, arms straight, core engaged. Retract shoulder blades (squeeze together), lowering your chest slightly. Protract shoulder blades (push apart), returning to the plank. Repeat with control.
Focus on shoulder blade movement, not elbow bend. Keep your core engaged. Perform slowly for full range of motion. Maintain a neutral neck. Incorporate into warm-ups to activate the serratus anterior.
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