Osteopenia- a risk factor for curve progression?

Low bone calcium has been found and noted in approximately 50% of AIS females in which their curve progressed 6 degrees or more and especially in the femoral neck of the hip on the side of the curve convexity (the outside of the curve) due to more weight bearing loading on the side of curve concavity (the inside of the curve). The researchers feel some of these findings could be explained via low calcium in take, but felt that a lack of weight bearing activity and programmed exercise due to spinal brace treatment may be a primary contributer to the osteopenia in AIS.