Movements of the torso or trunk are enabled by the bony architecture of the vertebral column. This axial stack of bones can move individually within a small range of motion and collectively through a much greater range of motion. The vertebral column is anchored via the sacrum, located between the bones of the two hip joints.

Three large dietary trials in the late 60s and early 70s—the Dayton or LA Veterans Trial, the Finnish Mental Hospital Trial, and a corn oil trial—were used to substantiate the central claims of the diet-heart hypothesis, specifically that dietary saturated fat and cholesterol increase blood cholesterol and heart disease risk. These trials, however, each had flaws in their design, outcomes, or interpretation that undermine their use in support of this conclusion.