Side-lying external rotation

Lie on your side and rotate your top forearm toward the ceiling — an equipment-free external rotation for the rotator cuff and upper back.

How to do it

1. 01Lie on your side with your head resting on your bottom arm or a pillow, knees slightly bent for stability.
2. 02Rest your top upper arm along your side with the elbow on your hip, bent to 90° so the forearm lies across your belly.
3. 03Keeping the elbow in place, rotate your forearm up toward the ceiling as far as is comfortable.
4. 04Pause at the top, feeling the back of your shoulder work, then lower slowly.
5. 05Do all reps on one side, then roll over to train the other arm.

Common mistakes

• Elbow lifting off your hip — keep it against your body and rotate only the forearm.
• Rolling back to lift higher — keep your hips and shoulders stacked and stop at a comfortable range.
• Letting the arm drop — lower as slowly as you lift; when it gets too easy, pause longer at the top.