The incline bench bicep curl is similar to a preacher curl, in the way it lets you isolate the bicep muscle.
While preforming a standing bicep curl it will engage your anterior deltoids and trapezius muscles to help stabilize the movement.
You will generally be able to lift more using the traditional dumbbell curl because less tension is placed on the biceps.
Using the bench allows you to isolate the bicep muscle, putting all the pressure where it needed to be.
Perform this exercise in a slow controlled manner throughout the full range of motion for best results.
Proper positioning of your arm on the bench is crucial in order to execute this movement safely and effectively. You should avoid placing your elbow on the very end of the bench since this will cause issues with your tendons and ligaments along with placing too much unneeded stress on the elbow joint. Tuck your armpit into the end of the bench and lay your arm flat on the bench pad.