Is the trapeziums the main muscle used during barbell shrugs?

Yes, the trapezius muscles are the primary muscles used during barbell shrugs. This exercise primarily targets the upper portion of the trapezius, which is responsible for elevating the shoulders. Additionally, other muscles such as the levator scapulae and the rhomboids may also be engaged to a lesser extent during the movement. Overall, barbell shrugs are effective for building strength and size in the traps.