Rotation + Hammer Curl Combo - Duration: 0:16. - Duration: 7:42. The ONLY Way You Should Be Doing Dumbbell Bicep Curls! Mind Pump TV 1,754,406 views. One-Arm Palm-Down Wrist Curl Rotation Sit on the corner of a bench or a chair with one dumbbell in your right hand. Grip the dumbells with an overhand grip and place your wrist on your right knee with your palm facing down. John Rusin 872 views. Set your right feet firmly on the floor and make sure your right thigh is parallel to the ground.