In the sense that there's generally not very much there to be sturdy. I can't think of any highly durable materials or construction methods that are suitable for shoes that aren't also relatively bulky, which minimalist shoes are often striving to get away from. It's a tradeoff. I don't think it's something they're designing for. There's likely an opportunity here, but I'm not sure how big the market is, particularly at prices that would be competitive.

Got it. Thanks!