In a car accident what is the legal cause. In Wisconsin, to successfully recover money damages from another driver who caused a car accident or collision, the injured person must prove four things: duty, negligence or breach of the duty, causation and damages. This post will discuss causation.
In lay terms, an injured person can recover money damages from the negligent driver for those damages or injuries caused by the defendant's negligent conduct. For example, if a bad driver rearends someone and that innocent person develops pneumonia two weeks later and ends up in the hospital, there is likely no case. There is no case because there is no doctor who will testify that the pneumonia was caused by the car accident. There has to be a causal link between the negligent conduct and the injury, usually it is the accident and whatever injuries a doctor can say are more likely than not as a result of the accident.
If a case goes before a jury, in Wisconsin civil jury instruction 1500 defines cause as follows:
... you must decide whether someone's negligence caused the injury. This question does not ask about "the cause" but rather "a cause" because an injury may have more than one cause. Someone's negligence caused the injury if it was a substantial factor in producing the injury. An injury may be caused by one person's negligence or by the combined negligence of two or more people.
It is common for people injured in auto collisions to have some pre-existing medical condition, such as low back muscle pain or even a bulging disc in the cervical or lumbar spine. If an accident aggravates or makes the condition worse, then the negligent driver is responsible. Wisconsin civil jury instruction 1715 on aggravation states:
The evidence shows that the plaintiff was previously injured when this accident happened. If the injuries of the plaintiff received in the accident aggravated any physical condition resulting from the earlier injury, you should allow fair and reasonable compensation for such aggravation but only to the extent that you find the aggravation to be a natural result of the injuries received in the accident.
McCormick Law Office attorneys get the best results in car accident cases by carefully reviewing the client's medical records and where appropriate asking the treating physician to answer questions or write a report addressing the causation question. Some doctors are reluctant to get involved in legal cases or misunderstand the degree of proof required on these questions. If a doctor is unwilling to help we may seek out an independent physician to examine the client, review records and issue a report.