As a dictionary says the word "heel" has general meaning to leg's heel and shoes' heel, so when I talk about 'Heel' as a name of the part of a leg what more exact word can I use? The same question is to a name of the part of a women's shoes.
Context makes it clear. If absolutely necessary you can say "shoe's heel" or "foot's heel", or similar.
I'm wearing a cast because I dropped a stone on my foot. My heel and ankle were crushed. Incredibly, the heel of my shoe didn't break.
Context makes the first reference "heel" completely clear. In this artificial situation the second reference to "heel" would be unclear if not written with "of my shoe".