Hit the rear delts that finish off a 3D shoulder.

Keep a flat back and lead with your pinkies, don't turn it into a row.
Hinged to near parallel with palms facing each other, the rear delt raise lifts the dumbbells out level with your back, loading the rear delts through the exact plane where they pull. Leading with the pinkies keeps the arc in the delts instead of drifting into a row, while the upper back assists to steady the spread. Rear delts are what make shoulders look built from behind, and this raise is the most direct dumbbell route to them.
The hinge. Bent to near parallel, raising out to the sides targets the rear delts, standing tall the same motion hits the side delts. Same tools, completely different head of the shoulder.
Your elbows are bending and pulling backward instead of the arms sweeping out. Keep the elbows soft but fixed, lead with your pinkies as the cue says, and lighten the dumbbells until the arc stays wide.
Higher reps, around 12 to 20, suit them best. The rear delts respond to volume and strict tension, and light weight for more reps is far easier to keep honest than heavy sets of eight.




