hey, i've been riding a proper trials bike for about a month and a half now and veryting is progressing well. However, i run front and rear maggie's and since i have been riding it seems my index fingers have developed callus's and every so often a blister, at just the point where my finger pulls on the lever. Also, on my left index finger it seems i have sprained it or something but its very painful to pull on my rear brake and even to bend it. I was wondering what would cause this to happen? Or whether a replacement lever (e.g) Gu etc. would stop this from happening. all opinions welcome