Individuals who suffer injuries following motor vehicle accidents or slip and falls are often concerned that their pre-existing injuries may reduce or negatively impact the compensation they are looking to receive.  This is a valid concern as lawyers for the defendant will examine the injured victim’s medical records for any prior medical conditions. 

As a general rule, in assessing damages a judge will only put an accident victim back to his/her original position before the accident occurred.


The Supreme Court of Canada, in the case of Athey v Leonati, established the principle that you take your victim as your find them.  An accident victim is therefore entitled to be restored only to the position that he/she would have been in but for the accident.  Generally speaking, if the accident caused an aggravation or exacerbation of an existing condition, you are entitled to be compensated for that injury.  You are not entitled to be placed in a position better than your original position before the accident.

It is therefore necessary to determine what the accident victim’s condition was before the accident.


What is meant by the term thin skull?

The term thin skull applies to those individuals who are vulnerable to injury or more fragile than the average person as a result of a pre-existing medical condition.

In personal injury law, the negligent party(s) must take their victims as they find them.  A defendant is liable for the plaintiff’s injuries even if the injuries are severe because of a pre-existing yet stable condition.  The thin skull rule is the principle that although an accident victim may be more susceptible to an injury this does not relieve a negligent party of liability.  This rule prevents a negligent party from avoiding liability by blaming the victim for the injury.

In order to recover damages, accident victims with a pre-existing conditions must prove the following in order to recover damages:

  • The nature of the pre-existing condition;
  • That the condition was stable prior to the latest accident; and
  • That the accident caused a worsening of the pre-existing condition.

Therefore, insurance companies cannot argue that you are entitled to less compensation for your injury because a person of greater strength would have been less injured or quicker to recover.  All accident victims are entitled to be restored to the position they would have enjoyed but for the accident.

What is meant by the term crumbling skull?

The term crumbling skull refers to those individuals with an unstable pre-existing medical condition that would have left them impaired whether or not they were injured in the subject accident.  Therefore, individuals with a “crumbling skull” are not in a stable condition before the accident, rather a state of continuing deterioration which the accident has simply fast-tracked.  Thus, the accident victim would have eventually suffered from the condition in question regardless of whether he/she was involved in the accident. 

In these circumstances, the negligent defendant is responsible for any additional damage, but not for the pre-existing damage.  A pre-existing condition that was unstable and would have worsened over time is subject to the crumbing skull rule when determining the extent of the negligent party’s liability.


An accident can make your pre-existing issues worse (an aggravation or exacerbation of a pre-existing injury) or cause a condition that was previously asymptomatic to become symptomatic.  All injuries sustained as a result of a car accident or slip and fall are compensable. 

The accident victim’s medical records are the most important records to prove the nature of a pre-existing condition and whether or not this condition was stable at the time of the accident.  Past medical records and more recent medical evaluations since the accident are required to prove the validity of your claim.  These records that can show the diagnosis, treatment taken and ongoing prognosis are useful in proving an injury or disability.

Records such as clinical notes from doctors, diagnostic test reports, office appointment histories, treatment records, laboratory tests, hospital records and account or billing statements are all important documents which may illustrate the severity or nature of the injuries.

The personal injury lawyers at Cuming & Gillespie LLP have many years of experience successfully handling cases for compensation by those who have suffered injuries in accidents caused by the negligence of third parties. 

If you have suffered injuries as the result of someone else’s negligence, please contact the personal injury lawyers at Cuming & Gillespie LLP.  Our legal team is made up of knowledgeable lawyers capable of handling a wide range of personal injury cases, including those involving pre-existing conditions.  It is important that you call us promptly so we can help you understand your rights and the potential to recover compensation for your injuries.  For a free evaluation, please contact our office online or at 403-571-0555 to make an appointment.  We look forward to helping you obtain the compensation that you deserve.