Flip the grip and the rear delts light right up.
Squeeze the shoulder blades and keep your neck long, don't shrug.
Flipping to a palms-forward grip changes where a bent-over raise lands. The underhand position rotates the arm so the rear delts catch more of the tension as you sweep the dumbbells out level with your torso, while the muscles of your upper back assist with the squeeze at the top. It is a smart swap when standard rear delt raises have gone stale, and it thrives on light weight and strict control.
The palms-forward, thumbs-out position rotates the shoulder in a way that biases the rear delts and gives a different feel at the top of the rep. If regular bent-over raises always end up in your traps, this variation is worth a run.
Light. Rear delts respond to strict reps and time under tension, and heavy dumbbells just invite swinging and shrugging. If you cannot pause briefly at the top, drop the weight.
You are shrugging as you raise. Keep your neck long, hinge properly so your torso is near parallel, and think about pushing the dumbbells out wide rather than lifting them up.
