But slouching has other pernicious effects besides slowing your squat gains. According to Dr. Jason Quieros, a chiropractor at Stamford Sports and Spine in Connecticut, “every inch you hold your head forward [while slouching] you add 10 pounds of pressure on your spine.” If you’re like most chronic desk slouchers, you’re likely leaning your head towards your monitor by 2 or 3 inches. That’s 20 to 30 pounds of extra weight that your back and spinal column have to endure for extended periods of time.

In the short term, this can cause jaw aches and headaches, but in the long term it can result in kyphosis, or a permanently visible Quasimodo-esque hump on your upper back. Kyphosis isn’t just an aesthetic problem, either. It can cause pain due to excess strain on the spine, as well as breathing difficulties due to pressure on the lungs from the caved-in chest that comes with a rounded back.

via De-Quasimodo Yourself: 6 Exercises to Counteract Slouching | The Art of Manliness.