Final answer:
The sacral inclination involves several landmarks including the sacral promontory, sacral canal, sacral hiatus, sacral foramina, and the auricular surface. The normal sacral inclination angles range between 30° to 40°, contributing to pelvic posture.
Step-by-step explanation:
The key landmarks associated with sacral inclination are the sacral promontory, the sacral canal, sacral hiatus, sacral foramina, and the auricular surface. The sacral promontory is the anterior lip of the superior base of the sacrum. The auricular surface laterally joins with the ilium to form the sacroiliac joints. The sacral canal runs inferiorly through the sacrum and ends at the sacral hiatus, which is the inferior opening.
The sacrococcygeal curve is an anteriorly concave curvature formed between the sacrum and the coccyx, constituting a primary curve of the vertebral column. As for the normal and average angles of sacral inclination, these can vary among individuals but typically range between 30° to 40° in adults. This measurement can influence the overall posture of the pelvis and lumbar spine.