Injury compensation lawyer Mount Elliot: impairment explained

An injury can be serious in human terms and still sit on the threshold side of the line, and the reverse can happen too. That can feel unfair. It helps to know the scheme's tests are about the type of injury and its lasting effects, not how much you've suffered. Knowing which test applies lets you and your doctors focus on the evidence that matters.

A crash can cause psychological injury as well as physical injury, and sometimes instead of it. Some psychological injuries are classed as threshold injuries; others are not, depending on the diagnosis. Anxiety, low mood, flashbacks or fear of driving are worth raising with your GP early, both for your own sake and so the injury is recorded and properly diagnosed.

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%.

It's easy to overstate the 10% line. You don't need more than 10% WPI to claim damages for past and future loss of earnings; you need an injury that's more than threshold, another driver at fault, and not to have been mostly at fault yourself. The 10% line decides pain and suffering, and it also affects some timing rules for a damages claim.

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
• How complete and current your medical records are
• Scans or tests your doctors have ordered

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.

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.

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
• Operation and specialist reports
• Reports from a treating psychologist or psychiatrist, if any
• Records of how the injury affects your work