Apparently 2/3 of young adults have what's being called "work-from-home back"
The British self-care campaign Mind Your Back surveyed of 1,000 adults to see how the COVID-19 pandemic changed daily habits. They discovered that 2/3 of the respondents ages 18 to 29 had back pain that wasn't there before the pandemic. Most people felt the pain in their lower backs, which is typically a result of poor posture.
It's possible that people got more comfortable while working from home instead of using their normal set up, which could be better for their posture. Think: working on the couch rather than at a desk with a good office chair for about 8 hours a day.