Adolescent idiopathic scoliosis (AIS) is a spine deformity that affects human spine. In our research line we focused more on the intervertebral disc rather than the vertebrae. We hypothesized that AIS is caused by an overloading of the intervertebral disc. In the human spine, some levels are subjected to posterior directed force components of gravitational force which will unlock the facet joints. Unable to counteract the load via facet joints, the vertebral body can become rotationally unstable. If this would occur during this growth, when loads increase, this could lead to high disc strains. This could also be different for those who do and do not develop AIS. In this project, subject-specific spine models are built and subject-specific posture and daily-activity loading conditions will be applied taking into account the subject weight, body size and activity level, and thus will differ over time. This allows to investigated if the expected positive feedback loop (overstraining the disc leads to more deformation) can be observed, so that the hypothesis according to which Adolescent Idiopathic scoliosis is caused by an overloading of IVD can be confirmed.