Different regions (curvatures) of the vertebral column. [edit on Wikidata] A neutral spine or good posture refers to the three natural curves [that] are present in a healthy spine.. Looking directly at the front or back of the body, the 33 vertebrae in the spinal column should appear completely vertical. From a side view, the cervical (neck) region of the spine (C1-C7) is bent inward, the thoracic (upper back) region (T1-T12) bends outward, and the lumbar (lower back) region (L1-L5) bends inward.