Cathe, avoidance and or treatment for sore muscles?

[intensitylisa]

:-( Hi Cathe and all! It seems as though every time I do the PUB my lat muscles in the back of my shoulder blades are always extremely sore. My heaviest weight I use for the back are 15 lb dumbbells. Should I lighten this down to 12 lbs or do fewer reps with the 15's;-) Also is there something I can do to prevent muscles soreness? Any thoughts would be appreciated!