Let's face it, our backs have a fundamental design fault - they're not made to stand up to the extra stresses and strains placed on them by humans walking upright. The bones in our back need to be fixed together in a way that keeps them stable, but still allows enough flexibility to stop us moving around ramrod straight. This is possible because we have lots of small bones - the vertebrae - separated by 'discs' of tough connective tissue surrounding a squashy centre, as well as muscles and ligaments criss-crossing between them. Being upright means gravity is constantly compressing our spinal bones and discs.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/when-to-worry-about-back-pain