Does bad posture affect breathing?

People with extremely curved upper back (kyphosis) and internally rounded shoulders are more susceptible to depression of the sternum. While inhaling, the sternum can’t fully expand, and the motion of the ribcage is limited on the front side of your body.

An overstressed lumbar curve (lordosis), just like the posture, when your pelvis is inclined forward, will reduce the range of motion of your lower lumbar spine while also shortening the latissimus and lower back muscles. This, in turn, will shorten the crus of your diaphragm and restrict the range of motion of your diaphragm. When this happens, your breath’s expansion will decrease. As the stomach muscles are “over-contracted” in this posture, these muscles will not be able to function properly during exhalation.

Thus, sometimes individuals may face difficulty in breathing with an overstretched curve in the neck, in a condition called lordosis of the cervical spine, due to the compression of their larynx.