My back is like a bent driveshaft in two places. Causes me to be off balance.

T12/L1/L2 pushed forward/wedged/pushed backward. Physical therapist said
no matter how I stand it can't be straight.

Analogy I just used for first time today to try to explain this to him. 
A person who understands mechanical things might be able
to see the condition of my vertebra and possibly start to understand it.