Which muscles are integral in moving the humerus?

The pectoralis major and deltoids are indeed the primary muscles responsible for moving the humerus. The pectoralis major is a large muscle located in the chest that plays a critical role in shoulder flexion, adduction, and medial rotation of the arm. Its ability to pull the humerus across the body is essential for various movements, such as reaching and pushing.

The deltoids, which form the rounded contour of the shoulder, are also key players in humeral movement. This muscle group consists of three distinct parts—the anterior, lateral, and posterior fibers—each contributing to different motions. The anterior fibers assist in shoulder flexion and medially rotating the arm, while the lateral fibers are primarily involved in arm abduction. The posterior fibers help with shoulder extension and lateral rotation.

Together, these muscles facilitate a wide range of movements of the arm, including lifting, throwing, and pushing, making them integral to humeral action. Understanding the specific functions and contributions of these muscles is essential for comprehending shoulder mechanics and overall upper body movement.