“Most people tend to round out their backs when they sit,” says orthopedic surgeon Nomi Khan. “Their spine is in an improper position, and they will tend to have more back problems.”
Back problems crop up because sitting like a C — or a cashew nut — can damage the little shock absorbers in the spine, called the intervertebral disks.
This story and gif changed my prospective on sitting. -Emily
If you say so, NPR.