What should be checked before relying on a WPI figure?
Check maximum medical improvement, the body area, objective findings, the NSW Guideline chapter and any NSW modification before relying on a percentage.
Can this page calculate your percentage?
No. WPI depends on an assessor, maximum medical improvement, objective findings and the NSW Guidelines. This page is general information only.
Permanent impairment assessment
How permanent impairment is assessed for Gait derangement, permanent walking aids and last-resort lower limb assessment
Gait derangement is not a convenient extra percentage. NSW treats it as a last-resort method. It cannot be combined with other lower limb methods, and any walking aid relied on must be permanent rather than part of short-term recovery.
What injuries can happen to this body part?
- Severe lower limb injury where no specific joint, nerve, arthritis, replacement, leg-length or amputation method properly describes the impairment
- Permanent aid dependence after a stable lower limb condition
- Complex multi-region lower limb impairment needing a no-double-counting analysis
Symptoms and findings that matter
- Why no more specific lower limb method is suitable
- Whether the gait abnormality is permanent and supported by pathology
- Whether a cane, crutch, brace or other aid is permanent
- Whether another method has already assessed the same impairment
What investigations are usually relevant?
- Treating specialist report and final impairment assessment at maximum medical improvement
- Imaging, pathology, audiology, ophthalmology, respiratory, nerve or functional testing that fits the body system
- Operative reports, discharge summaries, rehabilitation records and objective clinical measurements where relevant
How WPI is assessed for this body part
- Gait derangement is not a convenient extra percentage. NSW treats it as a last-resort method. It cannot be combined with other lower limb methods, and any walking aid relied on must be permanent rather than part of short-term recovery.
- Assessment source: NSW Guidelines Chapter 3 paragraphs 3.10-3.12 and AMA5 Table 17-5 as modified by NSW, including deletion of the Trendelenburg item.
- The assessor should explain maximum medical improvement, the body-system chapter, the method selected, any NSW modification, and why the objective findings fit that method.
How movement affects the assessment
- Gait derangement can describe walking function, but it is not combined with ROM, arthritis, nerve or replacement methods.
- Temporary post-surgical gait changes should not be used as permanent impairment evidence.
NSW gait derangement limits
Last resort onlyUse gait derangement only where no more specific lower limb method adequately assesses the impairment.
No combinationDo not combine gait derangement with another lower extremity method such as ROM, arthritis, muscle atrophy, nerve impairment or replacement scoring.
Pathological supportThe gait finding should be supported by objective pathology and examination findings, not only subjective walking difficulty.
Trendelenburg deletionNSW deletes the Trendelenburg item in AMA5 Table 17-5 because it is considered insufficiently reliable.
NSW lower limb global rules
Most specific method firstUse the method that most specifically addresses the lower limb impairment where possible, rather than a broad fallback label.
Highest valid assessmentWhere more than one valid lower limb method applies, the NSW Guidelines generally require the assessment that gives the highest valid rating, unless a specific rule prevents it.
Do not exceed amputation valueA lower limb part or region cannot exceed the applicable amputation value. The whole lower limb maximum is 40% WPI, except where a specific gait table gives WPI directly.
Gait derangement is last resortGait derangement should be used only as a last resort and cannot be combined with other lower extremity assessment methods.
Permanent walking aid onlyIf a walking aid is relied on, the evidence should show permanent use, not a temporary aid during treatment or recovery.
ROM reliabilityROM can be unreliable where effort, pain behaviour or inconsistency affects measurement. The opposite side should be compared where relevant.
Arthritis needs imagingArthritis/cartilage loss must be radiologically assessed. Pain, crepitus or a broad MRI comment is not enough by itself.
Practical WPI examples
- A worker using crutches during post-operative recovery should not be rated as permanent gait derangement on that fact alone.
- A worker with ankle replacement should usually be assessed through the ankle replacement method rather than adding a gait figure.
- The NSW deletion of Trendelenburg means that item should not be used to support a gait rating.
Evidence checklist
- A clear diagnosis and the body area being assessed
- Records showing the condition has reached maximum medical improvement, if that is the issue
- Specialist reports, imaging reports and treating notes relied on by the assessor
- Objective findings on examination, not only symptoms described by the injured person
- A work and treatment chronology explaining the injury, treatment, surgery and recovery path
- Any previous injury, degeneration, congenital issue or non-work cause that needs apportionment considered
- Final specialist opinion explaining permanence
- Rehabilitation and gait notes
- Walking-aid prescription
- Imaging or examination findings supporting pathology
- Reasons other lower limb methods do not apply
What usually does not increase WPI
- Assuming a scan result automatically gives a WPI percentage
- Confusing pain, disability or inability to work with permanent impairment
- Ignoring maximum medical improvement before arranging an assessment
- Using an AMA5 table without checking whether the NSW Guidelines modify or replace it
- Double counting the same impairment through two methods when the Guidelines require one method
- Using gait because it looks easier
- Combining gait with another lower limb percentage
- Treating temporary aid use as permanent impairment
Assessment source
Assessment source: Assessment source: NSW Guidelines Chapter 3 paragraphs 3.10-3.12 and AMA5 Table 17-5 as modified by NSW, including deletion of the Trendelenburg item.
This section is source-backed general information. It is not a WPI assessment and is not legal advice.
- SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment: Source for the NSW assessment framework, MMI, AMA5 adoption, NSW modifications and exclusions.
- SIRA lower extremity chapter: Source for NSW lower extremity assessment rules, gait derangement limits and NSW-modified lower limb tables.
Related injury and claim pages
Need a practical claim check?
If an impairment percentage, medical assessment or insurer decision is affecting your NSW injury claim, send the decision or report for a practical review. This is general information only and does not guarantee any result.
Request a free claim checkAssessment scope for Gait Derangement WPI Assessment
The assessment scope for Gait Derangement WPI Assessment should be stated precisely before any percentage is considered. The file should identify whether that label describes the primary diagnosed condition, a symptom of another injury, a regional overview or one component of a broader impairment. Findings from another body area or diagnosis should not be transferred without explanation. The report should connect the stated condition to the correct NSW Guideline chapter, objective findings, treatment history and any permitted combination or apportionment method. This distinction is particularly important where similar page labels cover different clinical questions.
- Confirm the diagnosis and body area being assessed as Gait Derangement
- Separate condition-specific findings from overlapping symptoms or injuries in another body area
- Check that the selected NSW Guideline chapter and method match the condition actually assessed
- Explain any combination, apportionment or exclusion rather than relying on the page label alone
Start with maximum medical improvement
Permanent impairment should generally be assessed when the condition is stable and unlikely to change substantially in the next year. Treatment, surgery and rehabilitation history may affect whether the timing is appropriate.
Use the NSW Guidelines first
The NSW Guidelines adopt AMA5 in many areas, but NSW modifications prevail. Do not assume an AMA5 table applies without checking the NSW chapter and any public SIRA clarification.
Keep the assessment practical
A useful assessment file separates diagnosis, objective findings, surgery history, work capacity issues, apportionment questions and the body-area method used by the assessor.
Ask about an impairment issueDocuments and records
Injury evidence to organise early
The useful records depend on how the injury happened, when symptoms were recorded and how treatment or work capacity changed.
- Date, location and short description of the injury event
- Medical certificates, reports, scans, treatment records or hospital documents
- Employer, insurer, police, incident or venue records where relevant
- Photos, witness details, dashcam or other supporting material if available
- Income, superannuation, work capacity or leave records where relevant
- Letters, emails, claim numbers and decisions already received
Common questions
Injury evidence questions
Short general answers only. The right next step depends on the facts, dates and documents.
Is WPI the same as being unable to work?
No. WPI is a medical impairment measure. Work capacity, weekly payments, damages, treatment disputes and TPD issues are separate questions, although the evidence may overlap.
Does pain alone create a WPI percentage?
Not by itself. NSW workers compensation excludes AMA5 Chapter 18 on pain. Chronic pain is assessed through the underlying diagnosed condition where the Guidelines permit it.
Can secondary psychological symptoms be added to physical WPI?
In NSW workers compensation, secondary psychiatric or psychological impairment is not assessed as permanent impairment. Primary psychological impairment is assessed separately and is not combined with physical WPI.
Injury pathway enquiry
Not sure which claim type matches the injury?
Start with how the injury happened, what medical records exist and how work or daily activity has changed. The same injury can sit in different pathways.