There are two things that I have serious issues with due to the gross amount of body deformation they can cause. One is ballet. Dance is great, but ballet purposely deforms the human body and with intense study the deformation can affect muscular and skeletal development.

The other thing is high heeled shoes. Occasionally wearing a heel is fine. Wearing pointed six inch stilettos every day is bad. But since I'm a guy most people don't care what I say about this.

Luckily I am not the only one preaching about this. Adria, over at the Ergonomenon, has put together a great little rant on the evils of high heels in her Ergonomic Nightmare of the Week feature.