Which muscles cover the chest and allow the arms to swing?

The pectoralis muscles are the primary muscles that cover the chest and facilitate arm movement, including swinging. There are two main sections of the pectoralis muscles—the pectoralis major and pectoralis minor—each playing a key role in shoulder and arm mobility.

The pectoralis major, which is the larger of the two, is responsible for the movement of the arm toward the body, as well as the rotation and flexion of the shoulder joint. This capability allows the arms to move freely during various activities, such as swinging. The pectoralis minor, while smaller, assists in stabilizing the shoulder blade and can also contribute to shoulder movements.

In contrast, the latissimus dorsi primarily focuses on movements of the back and upper arms, the trapezius supports shoulder and neck movement, and the deltoids are responsible for raising the arms and rotating the shoulder. While these muscles contribute to arm and shoulder functionality, they do not primarily cover the chest area or enable the specific swinging motion of the arms like the pectoralis muscles do.