A one-arm lying extension where the dumbbell lowers toward the opposite shoulder or beside the head, letting you fix side-to-side imbalances and brace the working arm with the free hand.
Primary muscles
This information is general fitness guidance, not medical advice. Stop if you feel pain and consult a qualified professional.
Main muscles working (thicker lines)
Lie on a flat bench holding a dumbbell at arm's length straight above the shoulder, with the free hand on the working arm's biceps.
Keep the upper arm vertical, steadied by the free hand.
Bend the elbow to lower the dumbbell toward the opposite shoulder, or beside the head with the palm facing you.
Stop when the forearm is about parallel to the floor.
Extend the elbow to return to the start; finish the set and switch arms.
Breathing: Inhale as you lower, exhale as you extend.
Upper arm stays vertical
Free hand steadies, doesn't lift
Slow to the bottom
Letting the elbow drift out
Rushing the lowering
Pushing the arm up with the free hand
Use a light dumbbell you can control; it travels across the face.