Quote Originally Posted by KnottedYet View Post
Her pelvis is pointing at the sky, her thorax is more nearly horizontal, meaning her low back has to go into this exaggerated flexion to connect to the two. That shoves her abdominal contents up into her diaphragm and cuts down on her breathing efficiency and sets up her lumbar spine for some nice disc distortion and paraspinal muscle strain.

Either her core isn't strong enough to hold the rest of her lined up with her thorax (so she is tilting her pelvis up in an effort to control weight distribution and balance) or she isn't flexible enough (mostly hamstrings) to ride with the saddle/bar relationship on that bike.

Or maybe that saddle is so uncomfortable she just can't sit right...
OK, maybe I'm being lazy...what is the thorax?