articulations of vertebral arches : ligamenta flava - supraspinous ligament (nuchal ligament) - interspinal ligament - intertransverse ligament
sacroiliac: anterior sacroiliac ligament - posterior sacroiliac ligament - interosseous sacroiliac ligament
ligaments connecting the sacrum and ischium: sacrotuberous ligament - sacrospinous ligament
sacrococcygeal symphysis: anterior sacrococcygeal ligament - posterior sacrococcygeal ligament