Anatomy of the Back Region and Its Clinical Application

The back has an upper border bilaterally extending from external occipital protuberance, along the superior nuchal line, to the mastoid process; two lateral borders extending from the mastoid process, along the anterior margin of the trapezius, to the acromion, then vertically along the midaxillary line to the iliac crest; and a lower border extending from the middle of the posterior and upper margin of the sacrum, externally along the iliac crest to the inferior end point of the lateral border. According to C7 (vertebra prominens), the spinous process and the 12th rib, the back region is divided into the nucha, back, and lumbar-lower parts.