I took in an order for a customer with flat feet and here are some photos of the last that I had made.
Normally, I prefer to work with wooden lasts but because of the climate in Singapore and logistical issues, I find myself using more plastic lasts here.
Before and After
Here is a before and after shot of the last. The left shows the unmodified side while the right has been completed.
While the lasts are built to the customer's measurements, there are usually 2 main points that I pay attention to on flat feet, namely adding volume to the arch and reducing volume from the instep.
Here are some photos to illustrate.
Big piece of leather added to the arch
Notice that the instep has been shaved down significantly and is not as tall as the unmodified side.
This took the better part of a day to complete with a big part of time spent getting the lines to flow smoothly especially after adding and removing a big volume.
At this stage I will usually send the modified last to a last factory for duplication then work on minor adjustments for each sides. This saves me a significant amount of time and also ensures that the toes are identical.
So the next step is to just wait for the lasts to return and we can start on pattern making and on the trial shoes.