I am just a beginner, but it sounds like you might be keeping your entire hand closed during your backstroke. Usually people who use the kind of grip you're describing open up their fingers (ring/pinky) a bit on the backstroke...that allows you to have a longer backstroke without breaking your wrist 

JrockJustin said:My backswing was limited though and I think that has to do with how tight I was gripping it. Should I keep practicing with the straight wrist or do what is comfortable? Any advice would be greatly appreciated! Thanks in advance!
Justin