Comments like that might be annoying—but they’re not wrong.
Not maintaining good posture and adequate back support can add strain to muscles and put stress on the spine. Over time, the stress of poor posture can change the anatomical characteristics of the spine, leading to the possibility of constricted blood vessels and nerves, as well as problems with muscles, discs, and joints. All of these can be major contributors to back and neck pain
, as well as headaches, fatigue, and possibly even concerns with major organs and breathing.
Murat Dalkilinç gives the pros of good posture.