Chiro.Org Blog:

Although it may be easier to teach anatomy by dividing the body into arbitrary parts, a misinterpretation can be created. For instance, we find clinically that the lumbar spine, sacrum, ilia, pubic bones, and hips work as a functional unit. Any disorder of one part immediately affects the function of the other parts. We should also keep in mind that an axial kinematic chain of weight-supporting segments extends from the occipital base to the soles of the feet. Because the number of professional papers concerning the cause and diagnosis of low-back pain is voluminous, emphasis herein is placed on points that the author believes are important but not often emphasized in popular literature.