Serious injury? Injury compensation lawyer, Yagoona West

Two measurements do most of the work when an injury is serious. One is the threshold line, which separates soft tissue and some psychological injuries from everything else. The other is whole person impairment, a percentage that describes lasting impairment. Between them, they affect how long statutory benefits can run and what a damages claim, if you have one, can include.

Earning capacity compares what you could have earned without the injury with what you can realistically earn now. For a tradesperson with a damaged shoulder, or an office worker with a brain injury, that gap can be large and long-lasting. Record every change to your working life: hours, duties, roles you can no longer do. Those facts sit alongside the medical evidence.

The threshold line is a medical line drawn by legal rules. Your doctor diagnoses the injury; the scheme's definition decides which side it falls on. Sprains, strains and whiplash without nerve findings usually sit on the threshold side. Confirmed nerve damage, a tear, a fracture or a brain injury generally takes an injury beyond it. The insurer makes the call, and you can challenge it.

Getting the classification right early helps. If you have symptoms that could point to nerve involvement or a tear, such as numbness, weakness, locking or a joint giving way, describe them to your doctor. Whether tests are needed is a medical decision. If a diagnosis changes, make sure the insurer has the new evidence, because the classification may need to change with it.

Whole person impairment, or WPI, is a percentage that describes how much a lasting injury affects the body as a whole. It isn't a measure of pain, and it isn't a measure of what you've lost. It's a medical assessment made under set guidelines once an injury has stabilised. In a CTP claim, WPI matters mainly for damages: non-economic loss is only available where WPI is more than 10%.

Because so much can turn on a few percentage points, WPI assessments are often contested. Your treating doctors, the insurer's chosen doctor and, if there's a dispute, a medical assessor through the Personal Injury Commission may reach different figures. Keep every report, and get advice before accepting an assessment you think is wrong.

The scheme treats psychological injury seriously, but it still sorts it by diagnosis. A threshold psychological injury is generally handled like a threshold physical one. A more serious diagnosed condition may take the claim beyond the threshold. Because the difference turns on the diagnosis, the opinion of a treating psychiatrist or psychologist can matter a great deal.

In a serious injury claim, impairment often comes into focus well after the crash, once treatment has run its course. The Personal Injury Commission handles medical assessment where the insurer and the injured person disagree. If you think an assessment is wrong, the steps to challenge it are set out separately, and the deadlines are short, so act promptly.

• Whether the injury has stabilised
• Changes in your condition since the last report
• Whether you disagree with the result, and the deadline to say so

Serious injury claims rest on medical evidence gathered over time: hospital records, imaging, operation reports, specialist opinions, and treating doctors' notes that track your progress. Your own records add the human detail. Start collecting early, keep everything in date order, and make sure each doctor knows about all your injuries, not just the one they're treating.

• Imaging reports, such as X-ray, CT or MRI, where done
• Every Certificate of Fitness, in order
• Reports from a treating psychologist or psychiatrist, if any
• Any impairment assessment, and your response to it