how to do spider curl with dumbbells

this is a variation of curling for the biceps that is going to contract it to full capacity. if you do not have a bench, just try bending yourself forward.
the most important thing to consider is to make sure you do not move your elbow when performing this exercise, especially make sure you do not bring it back.
try supinated and neutral from time to time to challenge different muscles and fibers of your front arm.