Curl like you're showing empty pockets and torch the inner biceps.
Keep those elbows tucked and rotate hard, the supination is what hits the inner fibers.
Starting palms-in and rotating the pinkies outward as you curl works the biceps through both of its jobs at once, bending the elbow and supinating the forearm. That hard outward rotation with elbows pinned biases the inner, short-head fibres that straight up-and-down curls undercook. It is a finesse variation that rewards strict form over big dumbbells, ideal for rounding out an arm day.
Because the finish position looks like turning your palms out to show empty pockets. The gesture is the exercise, the outward rotation with elbows tucked is exactly what creates the unusual biceps stimulus.
Lighter than your standard curl. The rotation is the point, and heavy dumbbells make you skip it or let the elbows drift wide. If you cannot rotate the pinkies fully away at the top, drop a size.
A deeper squeeze along the inner biceps at the top, driven by the full supination. If it feels identical to your regular curls, you are probably curling first and rotating as an afterthought instead of rotating throughout the rep.
