The sponge behind the vamp collapsed.

Sponge collapse behind the vamp can be handled by a repairman in a shoe repair shop. Or do it yourself and refill it. The simple way is to add a new sponge, because the sponge behind your shoes has collapsed and needs to be filled with a sponge. However, it should be noted that shoe repair and DIY have their own advantages and disadvantages. The advantage of shoe repair shop is worry-free, but the most important thing is the skill of the repairman. If the craft is not good, it is better not to repair it. The advantage of doing it yourself is that it can save maintenance costs, but the disadvantage is that the technology may not be as good as that of professionals and needs to be measured by yourself.