Shortcut for adding strength to brushes

I know about shift f, but i would like the ability to add or decrease strength using a keybind. Theres a feature like this already for the brush size but not the strength, its [ or ]. Why i want this instead of shift f is because i use a tourbox and it has dials that would be perfect for changing the value in strength, i already have it set for brush size. I hope this is a feature u can add i assume it wouldnt be so hard since its been done for the brush size