What is Neutral spine?

Good posture refers to the "three natural curves are present in a healthy spine". It is also called neutral 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 region of the spine is bent inward, the thoracic region bends outward, and the lumbar region bends inward. The sacrum and coccyx rest between the pelvic bones. A neutral pelvis is in fact slightly anteriorly rotated which means the anterior superior iliac spines should be just in front of the pubic symphysis not in the same vertical line.