Functional anatomy and pathophysiology of axial low back pain: disc, posterior elements, sacroiliac joint, and associated pain generators.

Careful consideration of functional lumbosacral anatomy reveals the capacity for pain generation in the disc, zygapophysial joint, sacroiliac joint, and surrounding ligaments. However, the methods used to definitively implicate a particular anatomic structure in axial low back pain have limitations. Anatomically and biomechanically, the discs and posterior elements are inextricably connected to a dynamic biotensegrity network of ligaments, muscles, and fascia. This article examines key lumbosacral anatomic structures and their functional interdependence at the macroscopic, microscopic, and biomechanical level. Particular attention is given to the capacity of each structure to generate low back pain.