Instructions:

1. Sit on the stability ball with your feet flat on the ground and your back straight.
2. Hold a dumbbell in each hand with your palms facing inwards and your arms extended down by your sides.
3. Engage your core and slowly lift one arm up towards your shoulder, keeping your elbow slightly bent.
4. Pause for a moment at the top, then slowly lower your arm back down to the starting position.
5. Repeat the movement with the other arm.
6. Continue alternating arms for the desired number of repetitions.