What is the name of the large triangular muscle that covers the shoulders and helps lift and turn the arms?

The deltoids are the large triangular muscles located on the upper part of the arm and shoulder. They play a crucial role in allowing a wide range of arm movements, including lifting, turning, and rotating the arms. The anatomical structure and positioning of the deltoids enable them to provide strength and stability during various activities, whether in daily life or specific physical exercises.

Understanding the function of the deltoids in shoulder movement is important, especially in fields such as esthetics and physical therapy, where the ability to perform tasks that involve the upper body is often necessary. While other muscles mentioned have significant roles, they are involved in different movements: the pectoralis major primarily affects the chest and upper arm movement, the trapezius assists with the movement and stabilization of the shoulder blades, and the latissimus dorsi is mainly responsible for movements of the back and shoulders. The distinct role of the deltoids in lifting and turning the arms makes them the correct choice in this context.