Injury compensation lawyer Belmont: 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.

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
• Changes in your condition since the last report
• Whether you disagree with the result, and the deadline to say so

Serious physical injuries often bring a psychological toll: sleeplessness, anxiety, depression or trauma symptoms. These can be part of your claim in their own right. Tell your doctor how you're coping, and ask about psychology if it would help. Whether a psychological injury is threshold or more is a medical and legal question, and the insurer's decision on it can be reviewed.

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.

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.

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.

Because serious injuries take time to show their full effect, evidence builds in layers. Early records show the injury happened and how bad it was. Later reports show how it has settled and what it has left behind. An independent lawyer can help spot gaps, but the underlying evidence comes from your treatment. Getting good care is also how good evidence is made.

• Hospital admission and discharge records
• Imaging reports, such as X-ray, CT or MRI, where done
• Reports from a treating psychologist or psychiatrist, if any
• Any impairment assessment, and your response to it