system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What causes that stoop in old folk where their head and neck are permanently bent forward?
gpt
Its called kyphosis, and its a number of things that cause it - fractures from weak bones (wedge fractures), discs that dehydrate and become deflated, and a lack of strong back muscles to hold a more upright posture. Because there is more weight in front of the spine than behind, all these forces tend to result in the spine curving forward through the upper thoracic (high chest) area.