Why do body's structures deteriorate and collapse?
Movement was designed to be easy. If our ancestors didn’t move, they didn’t eat, they didn’t survive. We all know the principle “use it or lose it”, or "you get good at what you do". Our ancestors used it, meaning they moved a lot, and so could always do it.
In the last 40 years living patterns have dramatically changed and people now "living online" sit-hunched over (digital device) almost constantly. Physiotherapy research shows in no longer moving, or using it, we lose inner, deep foundational muscles designed to hold us up.