Dumbbell 90 Degree External Rotation

Raise your arms out to shoulder height and bend your elbows to 90 degrees, with your forearms pointing toward the floor. Align your shoulders and elbows at the same height, and brace your abs to keep your torso still.

Keep your elbows and shoulders at the same height as you rotate only your forearms up toward the ceiling. Do not press with your whole arm; think of rotating your forearm around your elbow.

Pause briefly when your forearm is nearly perpendicular to the floor, then slowly return at the same pace. Keep your shoulder height from dropping throughout the way down.

Focus on the rotator cuff in the back of your shoulder rotating your forearm while your arm stays lifted. If your shoulder shrugs or you feel the front of the shoulder taking over, reduce the weight and reset your elbow height.

If your shoulder height drops or your elbow shifts forward and back, your whole shoulder and traps take over instead of the rotator cuff. Chasing heavier weight reduces the forearm's rotation range, so use a light weight through the full range.

Exhale as you raise your forearm and inhale as you lower it. Steady breathing helps you keep your shoulder height and elbow position much more stable.

This movement should feel like the rotator cuff is holding the position on its own, not like your shoulder is being compressed. Start much lighter than a standard external rotation, and increase the weight only while you can keep shoulder height intact.