liminfoDermatome Reference
Free web tool: Dermatome Reference
| Level | Innervation Area | Clinical Significance |
|---|---|---|
| C2 | Posterior scalp | Occipital neuralgia |
| C3 | Neck | Neck pain evaluation |
| C4 | Shoulder top | Phrenic nerve (C3-5) |
| C5 | Lateral arm | Deltoid reflex |
| C6 | Thumb, radial forearm | Biceps reflex |
| C7 | Middle finger | Triceps reflex |
| C8 | Ring+little finger, ulnar forearm | Finger flexion evaluation |
| T1 | Medial arm | Horner syndrome |
| T4 | Nipple line | Thoracic anesthesia level |
| T6 | Xiphoid process | Upper abdominal sensation |
| T10 | Umbilicus | Abdominal surgery anesthesia level |
| T12 | Upper inguinal region | Lower abdominal sensation |
| L1 | Inguinal region | Iliohypogastric nerve |
| L2 | Anterior thigh | Hip flexion |
| L3 | Medial thigh | Patellar reflex |
| L4 | Medial lower leg, big toe | Patellar reflex, dorsiflexion |
| L5 | Lateral lower leg, dorsum of foot | Toe dorsiflexion |
| S1 | Lateral foot, sole | Achilles reflex |
| S2 | Posterior thigh | Bladder function |
| S3-S5 | Perineum | Anal sphincter, saddle anesthesia |
About Dermatome Reference
The Dermatome Reference is a searchable clinical table covering all major spinal nerve levels from C2 to S5. For each level it lists the dermatome innervation area in anatomical terms, the English common name, and the clinical significance — including reflex associations, syndrome indicators, and anesthesia landmarks used in neurological examination and regional anesthesia planning.
Neurologists, anesthesiologists, physical therapists, orthopedic surgeons, and medical students rely on dermatome maps to localize nerve root pathology, assess spinal cord injury levels, plan epidural or spinal anesthesia, and interpret radiating pain patterns. This reference covers cervical (C2–C8), thoracic (T1–T12), lumbar (L1–L5), and sacral (S1–S5) levels in a single, filterable table.
The tool runs entirely in your browser. The search box filters all 20 entries in real time by spinal level code (e.g., "C6"), anatomical region (e.g., "thumb"), or clinical keyword (e.g., "biceps reflex" or "Achilles"). No server, no account, and no download are needed. The interface supports dark mode and is fully responsive on all screen sizes.
Key Features
- Complete dermatome table from C2 to S5 — 20 spinal levels in one view
- Real-time search filtering by nerve level, anatomical area, or clinical keyword
- Clinical significance column: reflex associations, phrenic nerve, Horner syndrome, anesthesia levels
- Bilingual labels — anatomical area shown in English with Korean anatomical names available
- Key landmarks: T4 (nipple line), T10 (umbilicus), S3–S5 saddle anesthesia clearly listed
- Color-coded level badges for rapid visual scanning of cervical, thoracic, lumbar, sacral segments
- Responsive table with horizontal scroll on narrow screens for comfortable mobile use
- 100% client-side — all filtering runs in the browser with no server requests
Frequently Asked Questions
What is a dermatome?
A dermatome is a region of skin whose sensory innervation is supplied primarily by a single spinal nerve root. Mapping dermatomes helps clinicians identify which spinal level is affected when a patient reports numbness, tingling, or pain in a specific area.
Which spinal levels are covered in this reference?
The table covers 20 clinically significant levels: C2, C3, C4, C5, C6, C7, C8, T1, T4, T6, T10, T12, L1, L2, L3, L4, L5, S1, S2, and S3–S5. These represent the most commonly tested levels in clinical practice and medical examinations.
What does the "Clinical Significance" column mean?
The clinical significance column lists the key reflexes, syndromes, or physiological landmarks associated with each dermatome level. For example, C6 is associated with the biceps reflex, T10 marks the umbilicus for abdominal surgery anesthesia, and S3–S5 covers the perineum relevant to saddle anesthesia.
How do I use the search to find a reflex level?
Type a keyword into the search bar at the top. For example, type "reflex" to show all entries that mention reflexes, type "C6" to jump directly to that level, or type "Achilles" to find the S1 level associated with the Achilles tendon reflex.
Why are not all thoracic levels listed?
The table includes the thoracic levels that carry the most clinical importance: T1 (medial arm, Horner syndrome), T4 (nipple line for anesthesia), T6 (xiphoid), T10 (umbilicus), and T12 (upper inguinal). Intermediate thoracic levels T2–T3, T5, T7–T9, and T11 are omitted because they are less commonly used as clinical landmarks.
Can I use this dermatome reference for anesthesia level assessment?
Yes. The reference includes key anesthesia landmarks: T4 (nipple line) for thoracic anesthesia level, T10 (umbilicus) for abdominal surgery anesthesia assessment, and S3–S5 for saddle anesthesia covering the perineum. These are standard reference points used in spinal and epidural anesthesia.
Is this reference suitable for neurological examination?
Yes, the table lists reflex associations for quick neurological level localization: C5 (deltoid reflex), C6 (biceps reflex), C7 (triceps reflex), L3–L4 (patellar reflex), and S1 (Achilles reflex). These are the deep tendon reflexes routinely tested in clinical neurological examinations.
How accurate is the dermatome data in this reference?
The data reflects the consensus dermatome map used in standard anatomy and neurology teaching. Dermatome boundaries vary somewhat between individuals and between different published atlases, so this reference is best used as a clinical guide rather than an exact boundary map.