Adjust seat so that it is not so low that the shoulders are elevated nor so high that you are hunched over the pad. Grasp handles with an underhand grip. Position elbows to sides. Raise the handles until elbows are fully flexed with the back of the upper arm remaining on the pad. Lower the handles until arms are fully extended. Do not allow muscles to relax before next repetition.
Here are a few suggested alternative exercises:Arm Curl - MachineBall Band Biceps CurlBarbell CurlDumbbell Curl