1. Hold a barbell at arms' length in front of the thighs, using an overhand
shoulder-width grip.
2. Keeping arms stiff, shrug your shoulders as high as possible, pulling the bar
vertically upward.
3. Lower the bar slowly down to the start position, stretching the trapezius.
Hand pacing: A shoulder-width or narrower grip on the bar emphasizes the trapezius. A wider grip works the deltoid as well.
Trajectory: Lift the bar straight up and down. Do not roll or rotate the shoulders.
Body position: Performing the shrug while standing vertically upright hits the muscle centrally. Tilting the torso slightly backward at the waist targets the upper trapezius in the neck, whereas leaning slightly forward hits the midsection of the muscle behind the shoulders.
Range of motion: The higher the bar is raised, the harder the trapezius works .
Muscles involved during the barbell shrug exercise:
Primary : Trapezius (upper and middle fibers).
Secondary : Levator scapulae, deltoid, erector spinae, forearms.