Functional movements are highly dependent on this part of the body, and lack of core muscular development can result in a predisposition to injury.
The core is used to stabilize the thorax and the pelvis during dynamic movement and it also provides internal pressure to expel substances (vomit, feces, carbon-laden air, etc.).
The core muscles align the spine, ribs, and pelvis of a person to resist a specific force, whether static or dynamic.
For these peripheral elements to remain static, and not move unnecessarily, the spine, pelvis, and rib cage must be aligned towards this end.
The nature of dynamic movement must take into account our skeletal structure (as a lever) in addition to the force of external resistance, and consequently incorporates a vastly different complex of muscles and joints versus a static position.
By incorporating movement, the bones of the body must absorb the resistance in a fluid manner, and thus tendons, ligaments, muscles, and innervation take on different responsibilities.