This is a seated dumbbell biceps curl. The prime movers are the biceps brachii, brachialis, and the brachioradialis. Sit on a flat bench preferable one that has a back support Sit on the bench holding each dumbbell at arm’s length The elbows should be right next to your waist Rotate your hands so they are facing your torso. This will be your starting position Begin by bringing your forearm on a direct line with your shoulder performing an arm curl. Keep your upper body stationary at all times slowly bring the dumbbells back to the starting position. For advanced lifters not extending the arms all the way down will maximize the biceps contraction.