Greetings, all. I hope I am posting this in the proper section.
In coach's article, Building the Olympic Body, the advanced front tuck lever is said to require a "flat" back, but the back of the young man in the photograph appears somewhat curved.

Clearly, the lad is strong (far more than I), but I thought perhaps this shot represents a slightly less-than-ideal capture of the static position. It may well simply be a matter of perspective.
All that to say, is a truly flat-back actually possible in this position or is it meant to be something resembling straight, such as that in the photograph?
(I'm aware this may be addressed in the book.)
Andrew
