How do you walk in these?

I don't wear heels much anymore. When I was in college, I wore them every so often. Even then though, I was in my flip flops, sneakers, or flat shoes mostly. Now, I will wear them like once a year or so...and that is about it. I wear a 2-3 inch wedge.

When I was in Marshalls, I saw a ridiculous heel. It is like 6 inches tall. How can you walk in something like that?! It has got to be so bad for your back. I will take my flip flops or sneakers any day. Thank you very much!