The pathogenesis of adolescent idiopathic scoliosis (AIS) has been the subject of many studies, but remains little understood. Previous work has shown that there is a correlation between the uncoupled spinal neuro-osseous growth and AIS. We believe that this uncoupled spinal neuro-osseous growth may also contribute to formation of normal curvature of the spine in the sagittal plane during the childhood. We speculate a three-dimensional spring model to better understand our hypothesis. The normal curvature of the spine, the uncoupled spinal neuro-osseous growth, and the overgrowth of the spine in the puberty may be the crucial factors in the pathogenesis of AIS.