Vertebrae Nerve Map -

⚠️ – Especially in lower thoracic/lumbar spine (e.g., L4 nerve root compression may occur at T12–L1 level). 4. Example Clinical Correlations | Symptom | Likely Level | |---------|--------------| | Numbness in thumb/index finger | C6 | | Loss of knee jerk reflex | L4 | | Numbness over medial foot & unable to heel-walk | L5 | | Numbness over lateral foot & unable to tiptoe | S1 | | Saddle anesthesia + urinary retention | Cauda equina syndrome (L5–S4) | 5. Summary The vertebrae-nerve map is a powerful clinical tool for diagnosing nerve root disorders, but it must be used with knowledge of anatomical variability and overlap . It is most reliable in the mid-cervical and mid-lumbar regions; caution is needed in transitional zones (C7–T2, L5–S2) and in the presence of congenital anomalies or prior surgery. Would you like a visual chart, a printable table, or more detail on a specific spinal level (e.g., lumbar radiculopathy patterns)?

⚠️ – Upper limbs (C5–T1) and lower limbs (L2–S3) have migrated from original segments.

⚠️ – A single vertebral body may not exactly correspond to the same-numbered nerve root (e.g., C7 nerve exits above C7 vertebra; T1 nerve exits below T1 vertebra).