Coccyx

Description

Framed in a lateral profile of the lower vertebral column, the distal lumbar spine (L1 through L5) transitions inferiorly into the sacrum and then the coccyx (tailbone), with the intervertebral discs interposed between adjacent lumbar vertebral bodies. The coccyx sits inferior to the sacral apex, angling anteriorly in keeping with the normal sacrococcygeal curvature. At the superior coccyx, the coccygeal cornua (superior articular processes) rise dorsally to meet the sacral cornua across the sacrococcygeal joint. Small structures, clear landmarks. This specific emphasis on the coccygeal cornua matters because they define the posterior margin of the sacrococcygeal articulation and are palpated during assessment of coccydynia, post-traumatic subluxation, and degenerative sacrococcygeal joint pain. A lateral view also clarifies how coccygeal angulation and segmental mobility can contribute to pain when sitting, and why targeted injections are placed at or just anterior to the sacrococcygeal junction rather than along the lumbar discs. For procedural teaching, the cornua help orient needle trajectory in ganglion impar block performed via the sacrococcygeal approach. Use this asset in musculoskeletal anatomy teaching (vertebral column and pelvis modules), pain medicine slide decks on coccydynia and ganglion impar interventions, or spine and pelvic floor chapters where readers need an uncluttered bony roadmap from L5 to the coccyx in a male adult. Anatomical accuracy verified by SciePro's Medical Advisory Board.