the reason being you boot is too big. grab a piece of foam and put it down the length of your boot, tighten the boot up as much as you can, buy another booster strap and put it in the inside of the boot if this still doesn't work. And if none of that works buy a new boot that is fitted properly
hope this helps
dude i just put on another pair of wool socks. it works great!
also try this while walking your dog, going to the store, or going out to dinner to take your shin muscles to a whole NEW level
but seriously shin excercises work. i used to get nasty shinbang everytime i went out and this is the only thing that really helped improve it.