E-Z curl's good for preacher curls using a close grip, but for standing curls it compromises direct biceps work while hitting the brachialis & forearms more. Not a bad thing but not as direct when it comes to biceps work.
If your wrists hurt or you just need a break try other standing curl alternatives after letting the injuries heal. Standing DB curls that will allow more freedom of motion and should stress the joints less, or standing cable curls that won't hurt the wrists the same way. Or do other biceps exercises instead.