I’m just going to make this post to explain Parker Cannon’s “sunken chest” to those of you who are unaware of what it is. Parker has pectus excavatum or PE. The appearance of a sunken chest is caused by his ribs formation. According to this website, PE only makes your lung capacity slightly below average so he is still able to sing even with this deformity. Don’t take my word on this, but I don’t think Parker’s PE hurts his lungs much(otherwise he wouldn’t be able to handle long tours as a vocalist), but varying from person to person it can cause chronic pain to the lungs. You can read more about pectus excavatum here.