I walk on the outsides of my feet. If there is a muscular weakness, what would it be? Weak abductors/tight adductors that pull my leg in? Weak VMO, strong lateralis?
There is a LOT more to gait patterns than weak or tight muscles. No one can even begin to answer this without a thorough gait specific exam. You have to consider anatomical foot variants, muscle sequencing, spinal bracing, tissue extensibility, type of shoe, previous trauma or injury, etc. etc. etc.