Now I have all the information needed for a comprehensive, step-by-step ASIA scale assessment guide.
ASIA Impairment Scale (AIS) — Step-by-Step Assessment
Full name: International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI)
Developed by: American Spinal Injury Association (ASIA) & ISCOS
Best timing: Complete within 72 hours of injury
THE ISNCSCI WORKSHEET
The official ISNCSCI worksheet: motor key muscles (left/right), sensory key points (light touch + pin prick), dermatome map, and scoring totals
BEFORE YOU BEGIN — PREPARATION
- Position patient supine for testing (standard position)
- Explain each test to the patient before performing it
- Test right and left sides independently
- Record results directly on the ISNCSCI worksheet
- Mark NT (Not Testable) if a limb is immobilized, amputated, severely painful, or has contracture >50% ROM
- Mark with asterisk (*) if a non-SCI condition affects the score (e.g., peripheral nerve injury, fracture)
STEP 1 — SENSORY EXAMINATION
Test 28 key dermatome points bilaterally (C2 → S4-5).
Two Modalities Tested at Each Point:
| Modality | Tool | How to Test |
|---|
| Light Touch (LT) | Cotton wisp or fingertip | Brush lightly across the key sensory point |
| Pin Prick (PP) | Safety pin / sharp object | Apply sharp end; patient distinguishes sharp vs. dull |
Sensory Scoring Scale (each point):
| Score | Meaning |
|---|
| 0 | Absent — no sensation detected |
| 1 | Altered — decreased, impaired, or hypersensitivity |
| 2 | Normal — same as a normal reference area (usually face/cheek) |
| NT | Not testable |
Key Sensory Points (C2 → S4-5):
| Level | Landmark |
|---|
| C2 | Occipital protuberance |
| C3 | Supraclavicular fossa |
| C4 | Top of acromioclavicular joint |
| C5 | Lateral antecubital fossa |
| C6 | Thumb (dorsal surface) |
| C7 | Middle finger (dorsal surface) |
| C8 | Little finger (dorsal surface) |
| T1 | Medial antecubital fossa |
| T2 | Apex of axilla |
| T3–T12 | Follow intercostal/abdominal landmarks |
| T10 | Umbilicus |
| T12 | Inguinal ligament (midpoint) |
| L1 | Half-distance between T12 and L2 |
| L2 | Anterior-medial thigh |
| L3 | Medial femoral condyle |
| L4 | Medial malleolus |
| L5 | Dorsum of foot at 3rd MTP joint |
| S1 | Lateral heel |
| S2 | Popliteal fossa midpoint |
| S3 | Ischial tuberosity |
| S4-5 | Perianal area (combined zone) |
Maximum sensory score: 112 for LT + 112 for PP = 224 total
Sacral Sparing — Special Tests at S4-5:
| Test | Method | Record |
|---|
| Deep Anal Pressure (DAP) | Examiner inserts gloved finger into rectum, applies pressure | Yes / No |
| Voluntary Anal Contraction (VAC) | Ask patient to squeeze rectum around examiner's finger | Yes / No |
STEP 2 — MOTOR EXAMINATION
Test 10 key muscle groups bilaterally (5 upper extremity + 5 lower extremity).
Motor Grading Scale (MRC Scale, 0–5):
| Grade | Meaning |
|---|
| 0 | Total paralysis |
| 1 | Palpable or visible contraction only |
| 2 | Active movement, full ROM — gravity eliminated |
| 3 | Active movement, full ROM — against gravity |
| 4 | Active movement, full ROM — against gravity and moderate resistance |
| 5 | Normal — full ROM against gravity and full resistance |
| NT | Not testable |
Key Muscle Groups:
| Level | Muscle | Movement |
|---|
| C5 | Elbow flexors (biceps, brachialis) | Elbow flexion |
| C6 | Wrist extensors (ECRL, ECRB) | Wrist extension |
| C7 | Elbow extensors (triceps) | Elbow extension |
| C8 | Finger flexors (FDP — middle finger) | Finger flexion |
| T1 | Finger abductors (ADM — little finger) | Finger abduction |
| L2 | Hip flexors (iliopsoas) | Hip flexion |
| L3 | Knee extensors (quadriceps) | Knee extension |
| L4 | Ankle dorsiflexors (tibialis anterior) | Ankle dorsiflexion |
| L5 | Long toe extensors (EHL) | Great toe extension |
| S1 | Ankle plantar flexors (gastrocnemius/soleus) | Ankle plantarflexion |
Maximum motor score: 50 (upper) + 50 (lower) = 100 total
STEP 3 — DETERMINE SENSORY LEVELS (Right & Left)
The Sensory Level = the most caudal intact dermatome with a score of 2/2 for both LT and PP, with all levels above also scoring normal.
- Determine separately for Right and Left
- Record as e.g., Sensory Level R: C6, L: C7
STEP 4 — DETERMINE MOTOR LEVELS (Right & Left)
The Motor Level = the lowest key muscle with a grade ≥ 3/5, provided all muscles above it are graded 5/5.
- Determine separately for Right and Left
- In thoracic levels (T2–L1) where no key muscles exist → motor level = sensory level (if testable motor above is normal)
STEP 5 — DETERMINE NEUROLOGICAL LEVEL OF INJURY (NLI)
NLI = the most cephalad (highest) of all four levels (R sensory, L sensory, R motor, L motor)
This is the single level used to describe the injury (e.g., "C5 complete SCI").
STEP 6 — DETERMINE COMPLETE vs. INCOMPLETE
Ask three questions about S4-5:
| Finding | Meaning |
|---|
| VAC = No AND all S4-5 sensory = 0 AND DAP = No | → COMPLETE injury |
| Any of the above is preserved | → INCOMPLETE injury |
This is called sacral sparing — any preserved function at S4-5 = incomplete.
STEP 7 — DETERMINE AIS GRADE (A–E)
Follow this decision tree:
Is the injury COMPLETE? (No sacral sparing)
↓ YES → AIS = A
Is the injury Motor Complete?
(VAC = No AND no motor function >3 levels below motor level)
↓ YES → AIS = B (sensory preserved below NLI, not motor)
Are ≥ HALF the key muscles below NLI graded ≥ 3?
↓ NO → AIS = C
↓ YES → AIS = D
Are ALL segments normal (and prior deficit documented)?
→ AIS = E
AIS Grade Summary:
| Grade | Name | Definition |
|---|
| A | Complete | No sensory OR motor function at S4-5 |
| B | Sensory Incomplete | Sensation preserved below NLI including S4-5; NO motor function below NLI |
| C | Motor Incomplete | Motor preserved below NLI; < half of key muscles below NLI graded ≥ 3 |
| D | Motor Incomplete | Motor preserved below NLI; ≥ half of key muscles below NLI graded ≥ 3 |
| E | Normal | Sensation and motor normal in all segments (in known prior SCI patient) |
ND (Not Determinable): Used when levels or grade cannot be determined from exam results.
STEP 8 — ZONE OF PARTIAL PRESERVATION (ZPP)
- Only used in complete injuries (AIS A) where VAC = No AND DAP = No AND S4-5 sensory = 0
- ZPP = dermatomes and myotomes caudal to the NLI that retain partial innervation
- Record ZPP for sensory (R/L) and motor (R/L)
- If sacral sparing is present → ZPP is not applicable (NA)
QUICK REFERENCE SUMMARY TABLE
| Step | Task |
|---|
| 1 | Test 28 sensory points bilaterally — LT and PP (score 0/1/2) + DAP & VAC |
| 2 | Test 10 key muscle groups bilaterally (score 0–5) |
| 3 | Determine Sensory Level R & L (most caudal intact dermatome) |
| 4 | Determine Motor Level R & L (lowest muscle ≥ 3/5 with all above = 5/5) |
| 5 | Determine NLI = most cephalad of all 4 levels |
| 6 | Complete or Incomplete? (sacral sparing at S4-5) |
| 7 | Assign AIS Grade A / B / C / D / E |
| 8 | Document Zone of Partial Preservation (AIS A only) |
— Rockwood and Green's Fractures in Adults, 10th ed. 2025