Peripheral nerve injury
Carpal tunnel and upper-limb peripheral nerve injury after a motor accident
Median, ulnar, radial or plexus injury is different from a joint movement problem. The CTP method assesses the injured nerve through motor and sensory criteria; it does not use the AMA4 entrapment-neuropathy Table 16 or add general grip weakness.
Motor accident injury
How can this injury happen?
Car or passenger collision
Direct wrist compression, fracture swelling or prolonged immobilisation may affect the median nerve; traction can affect the plexus.
Motorcycle accident
Handlebar impact, fracture or traction during a fall can injure median, ulnar, radial or plexus structures.
Pedestrian or cyclist impact
A crush or laceration can injure a named nerve directly or lead to post-traumatic entrapment.
Injuries that can occur
- median nerve injury or post-traumatic carpal tunnel syndrome
- ulnar or radial nerve injury
- brachial plexus traction injury
- nerve laceration, compression or post-fracture neuropathy
Symptoms and functional problems
- anatomical numbness, paraesthesia or cold intolerance
- loss of thumb opposition or finger motor control
- dropping objects and impaired fine manipulation
- neuropathic pain or dysaesthesia in a named nerve distribution
Seek urgent medical assessment
Rapidly progressive weakness, threatened circulation or acute compartment pressure requires urgent assessment.
Clinical evidence
What findings matter?
The diagnosis should identify the nerve and level, objective sensory and motor loss, and accident causation. EMG/NCS may support localisation but does not replace clinical grading.
| Record or examination | What it may establish | What it cannot prove alone |
|---|---|---|
| Neurological examination | Maps sensation, motor function, muscle bulk and named nerve distribution. | Non-anatomical symptoms do not establish a nerve percentage. |
| EMG/NCS | May confirm lesion level, severity and denervation. | Clause 6.58 still requires the adopted tables and clinical assessment. |
| Imaging and operative records | Show fracture compression, nerve release, repair or laceration. | Surgery or decompression alone is not WPI. |
Movement in daily life
How movement affects real activities
Joint ROM may remain normal even when hand sensation or motor control is impaired. Real-life function includes thumb opposition, finger control and safe object handling, but the percentage must come from the nerve method.
Thumb opposition and median motor function
Buttons, pinch, holding a pen and handling small items.
Motor deficit is graded through Tables 12a and 15, not general strength Table 34.
Finger abduction and ulnar motor function
Keyboard use, spreading fingers and stabilising objects.
The anatomical nerve and affected muscles must be identified.
Protective sensation
Safe grip, temperature awareness and object recognition.
Sensory deficit or dysaesthesia uses Table 11a with Table 15.
Threshold injury is a separate question: a verified peripheral nerve injury is not merely a soft tissue strain. Symptoms alone, or carpal tunnel without accident causation, do not establish non-threshold classification.
Part 6 permanent impairment
How is CTP WPI assessed?
Clause 6.58 requires Table 15 together with Tables 11a and 12a for peripheral nerve lesions. Table 16 must not be used. Clause 6.53 prevents combination with other upper-extremity impairment unless there are separate injuries.
Measurement rules that apply
- Clause 6.50 requires active, not passive, range of motion for the impairment calculation. A goniometer should be used where clinically indicated, and unreliable movement should be repeated consistently before it is accepted.
- Clauses 6.51 and 6.52 permit a contralateral baseline only where the uninjured joint is a fair estimate of pre-accident mobility. The total upper-extremity impairment for each comparable joint is subtracted before conversion to WPI.
- Clause 6.67 prohibits upper-limb strength evaluation and AMA4 Table 34. A genuine peripheral nerve or muscle-bulk injury must use another permitted method without double counting.
| Method | CTP source | When it is relevant | Important limit |
|---|---|---|---|
| Sensory deficit and pain | Tables 11a and 15; clauses 6.58-6.60 | Anatomically verified sensory loss, dysaesthesia or paraesthesia. | Use the maximum grade value except for CRPS as clause 6.59 states. |
| Motor deficit | Tables 12a and 15; clause 6.58 | Named nerve motor loss supported by examination. | This is not Table 34 strength evaluation. |
| UEI to WPI | Table 3; clause 6.56 | Converts combined nerve UEI. | Table 16 entrapment neuropathy is prohibited. |
- Identify median, ulnar, radial or plexus level.
- Separate motor, sensory and dysaesthetic components as the method requires.
- Address pre-existing entrapment or systemic causes with objective evidence.
What cannot be combined?
- nerve impairment with joint impairment unless separate injuries
- Table 16 with the required Table 15 method
- general grip strength or muscle weakness rating
What does not establish WPI by itself?
- tingling without anatomical findings
- positive provocation test alone
- EMG wording without clinical correlation
- carpal tunnel release alone
Motor accident examples
Distal radius fracture followed by median neuropathy
The file must distinguish a separate accident-related nerve injury from temporary swelling and avoid duplicating wrist consequences.
Brachial plexus traction with normal joint ROM
Normal movement does not exclude nerve impairment; the named nerve motor and sensory method is used.
Claim file preparation
Evidence checklist
Assessment source
Upper-limb nerve WPI source
Assessment source: Motor Accident Guidelines v10.1 clauses 6.53 and 6.58-6.60; AMA4 Tables 15, 11a, 12a and Table 3. Table 16 must not be used.
Threshold injury: A verified peripheral nerve injury may be non-threshold; symptoms or an entrapment label without accident causation are insufficient.
What the assessor checks
- named nerve method
- motor and sensory components
- Table 16 prohibition
- separate injury combination rule
What does not establish the result by itself
- tingling
- provocation test
- EMG alone
- release surgery
Official sources
Related NSW CTP guides
Free claim check
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Frequently asked questions
- Is carpal tunnel assessed with AMA4 Table 16?
- No. Clause 6.58 expressly says Table 16 must not be used and directs the assessor to Table 15 with Tables 11a and 12a.
- Is EMG/NCS required?
- It can support localisation and severity, but the clinical motor and sensory examination remains important.
- Can grip weakness be added?
- No. General upper-limb strength Table 34 is prohibited.
- Can wrist ROM and median nerve impairment both count?
- Only if they arise from separate injuries and the combination complies with clause 6.53.
- Does decompression surgery set WPI?
- No. The permanent residual nerve impairment after treatment is assessed.