Balanced patient: PI of 35° and LL of 44°, with an adequate relationship between these (35–44 = –9°) and a neutral SVA with a TPA of 2°, without compensatory mechanisms, PT = 2° and SS = 33° (35° = 2° + 33°).Note. PI, pelvic incidence; LL, lumbar lordosis; SVA, sacral vertical axis; TPA, T1-pelvic angle; PT, pelvic tilt.