I don’t know what brought mine on, I have got flat feet, something I never knew until about 10 years ago, but have been wearing flat shoes or boots every day for about the same time. If I wear heels my calves ache ! Cant think of anything Ive done differently but past 2 or 3 months have been very painful. I cant take any anti inflammatories either as Im on a blood thinner. Its quite wearing isn’t it when you cant stop walking about !