Lean forward a little by flexing your hips and knees (not illustrated in image).
Raise your elbow to shoulder height and allow the dumbbell to hang straight down with your elbow bent at a 90-degree angle.
Keeping your elbow in the same position, exhale as you raise the dumbbell until it is level with your head by externally rotating your shoulder .
Inhale as you slowly lower the dumbbell to the starting position.
Repeat for the prescribed number of repetitions.
Repeat the exercise with your opposite arm.
Comments and tips
You can also perform the dumbbell Cuban rotation with both arms at the same time, either simultaneously or in an alternating fashion.
Use light weights because the target muscle is relatively small. Light weights will also help to avoid damaging your shoulder joint.
The dumbbell Cuban rotation is not about building muscle. It’s about promoting shoulder health by strengthening three of the four muscles of your rotator cuff (teres minor, infraspinatus, and supraspinatus; the remaining rotator cuff muscle is the subscapularis). The rotator cuff muscles and their tendons work to stabilize your shoulder, so strengthening them promotes a strong and stable shoulder joint.
The target and synergistic muscles are not labeled in the illustration because they are out of view.