Carnes Hill: when you might need an injury compensation lawyer

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.

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.

An assessment above 10% opens damages for non-economic loss and changes some timing rules as well. But many people with genuine, lasting injuries are assessed at 10% or less. That doesn't mean the injury isn't real, or that there is no damages claim. Economic loss, such as lost earning capacity, can still be claimed where the other conditions are met.

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.

Getting the classification right early helps. If you have symptoms that could point to nerve involvement or a tear, such as numbness, weakness, locking or a joint giving way, describe them to your doctor. Whether tests are needed is a medical decision. If a diagnosis changes, make sure the insurer has the new evidence, because the classification may need to change with it.

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
• Scans or tests your doctors have ordered

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.

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.

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.

• Imaging reports, such as X-ray, CT or MRI, where done
• Operation and specialist reports
• Reports from a treating psychologist or psychiatrist, if any
• Records of how the injury affects your work