(Context: I have no science background and am asking this out of curiosity. I am a fiction writer and I'd like to see if what I am thinking of has any scientific basis.)

 

If an external limiter is put on a section of the body's growth, what will happen to that section?

 

More specifically, I'm wondering what would happen if someone were to put a large keyring around their ankle at, say, age eight, and then for whatever reason left it there. What would happen when the body started naturally growing to that limit (that is, the size of the ankle reached the size of the key ring and by assumption of 'normal' human growth would try to KEEP growing)? Would there be pain BEFORE a bodily reaction (the restricted part falling off, restricted blood flow, etc) could take place?

 

And are there any notable examples of this?

Several forms of body modification are along those lines.

 

http://en.wikipedia.org/wiki/Body_modification#Applying_long-term_force

 

Hard to say what would happen exactly. My guess would be simple deformation if the site were kept clean. Foot binding and neck rings are probably the closest to what you are describing.

 

Amniotic band constriction may also be worth a look.

 

http://en.wikipedia.org/wiki/Amniotic_band_constriction