Global sagittal angle and spinopelvic sagittal alignment: a step toward investigation of sagittal plane deformity in upper lumbar disc herniation.

This study demonstrated a unique correlation between several spinopelvic parameters and GSA and the occurrence of ULDH. Lower PI, SS, and LL in T12-L1 and L1-L2 levels indicates a flat lumbar spine which may increase mechanical stress at these levels, thereby leading to disc herniation.