In the world of insurance there are really only three ways for an insurer to defend any claim.

The first and simplest way for an insurer to avoid payment is to be able to say that you are the one responsible for your injuries and so you cannot look to them for compensation.

The second way, and this applies in every case, is for the insurer to argue that your injuries are not that serious and so these injuries warrant very modest compensation.

The third way, and this is where your medical history is so important, is to simply blame something else. That something else, in the case of physical or psychological injuries, is your pre-accident medical condition.  Your pre-accident physical or psychological condition will be recorded in previous medical records (including counselling records), Worksafe records, and sometimes employment records.

Since these records were created at a time when you had no reason to believe that you would suffer the new accident injury, they can be considered relatively reliable. They can also be misused and misinterpreted by insurers who will attempt to argue that great significance should be placed upon minor or temporary past medical issues.

Do not be surprised when the normal procedure in a claim is to obtain your medical records going back three years pre-accident so that your pre-accident condition can be considered.

Your pre-accident records can also be used by your counsel to assist in explaining and proving your claim.  In the case where injuries are more severe or persistent than might be expected at first, an underlying but asymptomatic condition may help to explain your injuries (Take for example the middle aged woman with osteoporosis but no history of neck pain  After an injury such a person may have a much slower or less complete recovery).

It may also be the case that a previous and incompletely resolved injury (maybe you are left with ongoing nagging episodes of low back pain) is easily aggravated and the result is a more serious injury.  A previous problem can also lead to a prolonged recovery and a final outcome that leaves you with a more serious and frequent ongoing problem.