My sneakers often wear out in the lining, especially at the heel, before the rest of the shoe. So, I mend the inside of the back of the heels with either clear First Aid tape - or white First aid tape (which matches my white sneakers).
If the padding has totally worn through at the heel, you can also replace the worn padded lining with a piece of molefoam and glue it or tape the edges. You may have to keep after the tape, as it slips after a while, but it makes your sneakers wearable and comfortable, so you can get your full use out of them.
By pam munro
By Cheryl from Missouri (Guest Post) 03/27/2006
The reason your shoes may wear out in the heel lining is from taking off the shoes without untying them. Otherwise, your shoes may be too big, allowing your heel to lift in & out of your shoe.
By Syd (Guest Post) 03/28/2006
I have patched the inside heel area of sneakers by cutting a piece of fabric to fit the area and use Tacky Glue on the fabric and press in place and let dry thoroughly. Sure extends the life of the shoes!
I think it is the socks that get nubbies on the heel that acts like sandpaper on the shoe lining.
You bring up a good point and that very thing has happened to me. I hadn't thought about how to repair it either so thanks for the tip!