Custom orthotics. But they can be very expensive, so Spenco Total Support Max replacement insoles are the next best thing. Find them on amazon.
Now i got insoles from doctor. But I'm not sure about shoes right now, but doctor said "you should to choose wide shoes" Then I interest about 4E side. Yonex = SC6EX http://www.yonex.co.jp/products/badshoes/shbsc6wm.html Mizuno = WAVE FANG Wide (Release this month in Japan) http://products.mizuno.jp/c/item/7KM34509/017007001 And other brand ?
Victor also has a wide shoes model in the newest catalogue. btw: Wide is relative. You may try mainstream high end shoes too.
I'm not sure about Victor, because i can't find spec and detail of Victor products. I'm also interest victor 9000ACE, but I'm not sure about 3E or 4E. Normally badminton shoes are 3E.
