If you have tarsal tunnel syndrome, you already know the odd vocabulary of it: the burning along the sole, the electric zing that shoots into the arch or toes when you stand too long, the numbness that shows up at night for no reason you can name.

If you are reading this, there is a good chance your arch has started to flatten, the inner side of your ankle aches after a walk that never used to bother you, or standing on one foot to rise onto your toes has quietly become impossible.