Although asymptomatic adults stood with stable global balance, the sagittal spinal alignment of healthy subjects, newly divided in 5 sagittal types, varied significantly. Type 3 AP appears as a new and unusual sagittal shape with low-grade PI, very low or negative PT, and hyperlordosis. Whereas most asymptomatic adults stood with C7PL behind the hip axis, a sizeable portion had C7 in front of the hip axis. This could be a new controversial aspect of ideal spinal balance.

Level IV.

It seems that keeping the physiological morphology is the treatment of choice. For patients with degenerative scoliosis, reducing the kyphosis could work. We do not recommend to increase the lordosis and obtain a type 3 morphology with an anteverted pelvis because of the risk of PJK and poor functional results.

Level IV (e.g. case series).