What part of the shoe does everyone think this print came from? Obviously the outsole, but is it the heel? The toes / ball of the foot? Instep area?
I tried to draw around the outline of the area of tread that I can see. Honestly, I've been wondering if this print is actually from a shoe at all. Having outlined it, I do now think it is a shoeprint, we are seeing the upper part of the tread pattern. The heel, I believe is missing. It's odd, because the area of design (imo) is where the shoe needs most traction and most flexibility, but the design isn't really suited to either need.
I've been looking at the shoes of my family and almost none have single lines of tread going, unbroken, from side to side. If we could figure out the type of shoe (its purpose - walking, dressy, sandal, etc.) we could narrow the search down a bit.