Good posture refers to the "three natural curves that are present in a healthy spine.". It is also called<unk> . 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. The sacrum (tailbone area) (S1–S5 fused) and coccyx (on average 4 fused) rest between the pelvic bones. A<unk>  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.
Neutral spine
Iliac spine
Scalpel
Boot 
SLAC Wrist
Armstrong limit
Radium jaw
Anterior shoulder