Centennial Park: when you might need an injury compensation lawyer

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.

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.

There's usually no single moment when WPI is measured. Opinions may come from treating doctors, from doctors the insurer arranges, and, where the two sides disagree, from a medical assessment through the Personal Injury Commission. Timing matters, because injuries can improve or worsen for months. A lawyer can advise whether an assessment is premature before you rely on it.

• Whether the injury has stabilised
• Whether every injured body part is included
• Changes in your condition since the last report

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.

Weekly payments cover lost income for a limited time. For a serious injury, the bigger question is the future: will you be able to return to your old job, at the same hours and pay? If not, a damages claim may include past and future economic loss, provided the conditions for damages are met. That part of a claim doesn't depend on WPI above 10%.

The definition works by exclusion. An injury is generally threshold if it is soft tissue damage with no nerve damage and no torn tendon, ligament, meniscus or cartilage, whether the tear is complete or not, or if it is a psychological injury the scheme classes as threshold. Injuries outside that description, such as fractures, torn ligaments or brain injuries, are generally more than threshold.

The line also decides whether common law damages are open. With only a threshold injury, they generally aren't. With a more serious injury, you may be able to claim damages if another driver was at fault and you weren't mostly at fault. That is why a threshold decision is often the most important decision the insurer makes about a serious injury.

The most persuasive serious injury claims usually have consistent evidence: the same injuries described the same way, from the hospital to the GP to specialists, with no unexplained gaps in treatment. That consistency comes from telling each doctor the full story and following treatment plans. If a report leaves something out, ask the doctor about it rather than letting it pass.

• Hospital admission and discharge records
• Reports from a treating psychologist or psychiatrist, if any
• Records of how the injury affects your work
• Any impairment assessment, and your response to it