If you are 5'10" and can't touch rim you have a very low vertical. I could dunk when I was 13, but I was 5'11". I would recomend calf raises. All you need for these is a chair. You put 3-4 inches of the front of you foot on the chair, and pul up your body using the calves in that leg. Do it a lot with both legs every day, and your vertical will increase.