Sit on the ground and bend one knee to place your foot flat on the ground. Rest the elbow of the same side arm on the inside of your bent knee, forming a 90-degree angle at your elbow. Hold a lightweight dumbbell in your hand with your forearm vertical.

Keeping your elbow anchored to your knee, slowly rotate your forearm downward, internally rotating your shoulder. Rotate your shoulder externally until your forearm is nearly vertical or as far as your range of motion allows.

Keep your elbow stable on your knee throughout the exercise. Repeat for the desired number of reps before switching sides.