In a row, which muscle is the prime mover?

• A. Deltoid
• B. Biceps
• C. Pectoralis major
• D. Latissimus dorsi

Answer: (D)

When performing a row, the main action is pulling the arm back and toward the torso, which relies on extending the shoulder and drawing the elbow inward. The latissimus dorsi is the large back muscle that drives shoulder extension, adduction, and internal rotation, so it provides the primary power in the pulling motion. The biceps mainly assist by flexing the elbow, but that doesn’t move the shoulder itself, so it’s a secondary contributor. The pectoralis major can aid in shoulder adduction, but it isn’t the primary driver in this row movement, and the deltoid is more involved with lifting or moving the arm in other directions rather than powering the pull.