A popular variation of the dumbbell hammer curl is to lift the dumbbells with your palms facing straight out in front of you in the starting position. This is called an "offset grip" hammer curl . Master the hammer curls technique, discover its benefits and add the exercise and its variations to your training to help you build powerful arms. Learn the proper form and technique of hammer curl , a variation of dumbbell curl that targets your biceps and brachialis. Find out the benefits, common mistakes, alternatives and variations of this exercise.