dumbbell seated bent over alternate kickback

Sit on a bench with a dumbbell in each hand, palms facing inwards. Bend forward at the waist, keeping your back straight and parallel to the ground. Extend one arm straight back, keeping it close to your body, until your arm is fully extended. Pause for a moment, then slowly lower the dumbbell back to the starting position. Repeat with the other arm. Continue alternating arms for the desired number of repetitions.