it maybe a sign of old age and being slightly knocked knee. first the plantar fascia ruptured about six seven years back. now even playing just a two badminton social, the same foot feels sore, particular under the arch, at the abductor hallucis. checked out a few suggestion on youtube about strengthening the foot muscles, like the foot shortening exercise (where you try to scrunch up the foot by moving the ball of the foot closer to the heel), tried for a few weeks, didn't seem to be helping. aside from visitng a pediatrist and getting custom orthotics, which i am not too keen on, under the motto, use it or loose it kind of saying, as the extra orthotic support translates to the foot muscles actually doing less work. as of late this has become a chronic issue, where my foot is sore the day after badminton and have to resort to gimping around. whats worse, this problem is working its way up to the knee, and thats not good.
I have sympathy for your feeling that an orthotic might make a foot "weak" by propping it up. But it is obvious that the combination of your current anatomy with badminton is causing problems. If a table is tipped because of one short leg, it's not a crime to put a little shim under to balance things out. Give your orthotic a try..... in addition to the foot stretches and strengthening. There is no promise that it's the whole answer. But properly designed orthotics have helped many keep playing the game they love. [disclaimer: i am in no way affiliated with, nor profit from, the worldwide orthotic cabal].
didnt visit any doctor, but started using super feet shortly after my initial post. they are doing what they were designed for. no complaints so far.
