Fig. 2

Measurements of lumbar lordosis (LL), sacral slope (SS), intervertebral height index (IHI), intervertebral angle (IVA), and endplate concave angle (ECA). Cobb 1(red): LL; Cobb 2: IVA; Cobb 3: cranial ECA; Cobb 4: SS; IHI = (line 1 + line 2)/(line 3 + line 4) × 100%