Injury compensation lawyer Maclean: threshold and beyond

Most people never need to think about impairment percentages. If your injury is serious, you probably will. The scheme's rules divide injuries by type first, threshold or not, and then, for some entitlements, by the degree of lasting impairment. This page explains both in general terms. Your own claim depends on your diagnosis and on the insurer's decisions, which can be reviewed.

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.

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 every injured body part is included
• Changes in your condition since the last report
• Whether you disagree with the result, and the deadline to say so

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.

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.

WPI turns a lasting injury into a percentage. A doctor examines you and rates the impairment under the assessment guidelines that apply to motor accident claims. The number doesn't reflect how hard your life has become; it reflects measurable impairment. Even so, it can decide important questions, especially whether damages for pain and suffering are possible.

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.

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.

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