The sacrum is a large wedge shaped vertebra at the inferior end of the spine. It forms the solid base of the spinal column where it intersects with the hip bones to form the pelvis. The sacrum is a very strong bone that supports the weight of the upper body as it is spread across the pelvis and into the legs. Developmentally, the sacrum forms from five individual vertebrae that start to join during late adolescence and early adulthood to form a single bone by around the age of thirty. A ridge of tubercles along the posterior surface of the sacrum represents the spinous processes of these fused bones.
Members of Cyrus’s generation are more likely than their parents to think of gender as nonbinary. A recent survey of a thousand millennials ages 18 to 34 found that half of them think “gender is a spectrum, and some people fall outside conventional categories.” And a healthy subset of that half would consider themselves to be nonbinary, according to the Human Rights Campaign. In 2012 the advocacy group polled 10,000 lesbian, gay, bisexual, and transgender teens ages 13 to 17 and found that 6 percent categorized themselves as “genderfluid,” “androgynous,” or some other term outside the binary box.