Injury compensation lawyer McMahons Point: impairment explained

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.

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.

A serious injury can change more than the next few months of work. It can limit the kind of work you can do for years, or permanently. In a damages claim, that is called loss of future earning capacity, and it can be a significant part of a serious injury claim. It generally needs evidence from your doctors, your work history and sometimes vocational experts.

People are often surprised by how technical WPI is. It is assessed under guidelines that rate specific impairments, such as lost movement in a joint, and express the result as a whole-body percentage. More than 10% is the key line in CTP claims, because damages for non-economic loss, meaning pain and suffering, are only available above it. Loss of earnings doesn't need that level.

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
• Whether you disagree with the result, and the deadline to say so

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
• Imaging reports, such as X-ray, CT or MRI, where done
• Every Certificate of Fitness, in order
• Records of how the injury affects your work