Injury compensation lawyer Cabramatta: impairment explained

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.

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%.

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.

Impairment is generally assessed once an injury has stabilised, meaning it's unlikely to change much with further treatment. Assessing too early can understate a serious injury. The insurer may arrange an assessment, your own doctors may give opinions, and if the insurer and you disagree about the degree of impairment, the Personal Injury Commission can carry out a medical assessment.

• 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 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.

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.

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 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
• Operation and specialist reports
• Any impairment assessment, and your response to it