I have dreamed of skinny for years.
Skinny legs, skinny thighs - but never again of skinny heels! I recently slipped while wearing a pair of skinny heeled shoes (not too high, mind you) and sprained my knee. Okay, I'll admit it - I actually slipped TWICE before deciding not to wear them again!
The thinner the heel, the more unstable the shoe, regardless of the heel height. Slipping on smooth surfaces is an easy thing to do. Wider, chunkier heels can be just as appealing as the skinny heels and a lot safer to walk in.
If you must wear that favorite pair of shoes that happen to have a skinny heel, please make sure the very bottom of the heel is not worn out as this will really cause you to slip! Have your shoe maker replace the heel and ask them to use a slightly thicker material in the process. Your knees will thank you later!