1) Stand with your feet shoulder width apart with a slight bend in your knees. Grab a pair of dumbbells in both hands with your elbows behind your body and your palms facing upward. Pull your shoulder blades back and keep a bend in your elbows so that you can comfortably keep your elbows behind your torso.
2) Curl the dumbbells towards your shoulders by contracting the biceps. Make sure that your elbow is the only joint that is moving throughout this movement.
3) Slowly lower the weight back to your starting position.