The spine is made of 33 vertebrae among which 24 are moveable. The vertebrae are divided into regions: 1. 7 Cervical 2. 12 Thoracic 3. 5 Lumbar 4. 5 Sacral 5. 4 Coccygeal The 5 sacral bones and the 4 coccygeal bones are fused into two bones. The lumbar regions consist of 5 moveable vertebrae from L1-L5. The lumbar vertebrae are the largest vertebrae and their vertical height is less than their horizontal diameter. The vertebral body is larger and wider horizontally than longitudinally. The front is thicker than the back. The upper lumbar laminae are taller instead of wider while the lower lumbar laminae are wider instead of taller. The size of the vertebral body increases from L1 to L5. The vertebral foramen is triangular shaped. L5 has the heaviest body, the smallest spinous process, and the thickest transverse process. Functional components: • The vertebral body is the load-bearing structure • The vertebral neural arch protects the neural elements. • Helps with the movement of the body and increases the efficiency of muscle action: Flexion, extension, rotation, and side bending • Mobility and stability to the back • Mobility and stability to the spinal column • It is the attachment point of many muscles • Helps with balance