Degenerative spine biomechanics analyzes the ways in which aging, trauma, and stress destabilize and compromise spinal function. Spinal integrity is predicated on coordinated biomechanics between vertebrae, discs, ligaments, and muscles. Degenerative changes; particularly in intervertebral discs, reduce hydration and elasticity and produce instability, abnormal load distribution, and pathologies such as disc herniation, spondylolysis, and spinal stenosis. These alterations not only reduce the motion but also cause pain and neurological dysfunction. Computational models and imaging studies show complex interactions between structural deterioration and biomechanics. Clarification of these mechanisms is essential for the creation of therapies to preserve mobility and restrict disability in older persons.