Set up specifically for the Light side-lying external rotation. Lie on your side and stack the ribs and pelvis before you begin. Keep resistance intentionally low so position—not load—is the challenge.

Keeping the elbow planted, rotate the forearm upward by turning only at the shoulder.

Use this version to make the position repeatable before adding range, load, or speed.

Stop where you could hold the dumbbell still, then lower through the same path slowly. Use a load you can stop anywhere.