Individuals and their bodies react different to traumatic events. Whether a minor motor vehicle accident or a significant slip and fall, a person’s body will suffer an injury, while not unique in name, unique to that person. In Massachusetts and throughout most of the United States, the courts have adopted the “egg shell doctrine”.
Generally, the egg shell doctrine stands for the proposition that a person who becomes injured due to the negligence of another, cannot be penalized for any medical conditions they may have been dealing with prior to sustaining the new injury. For example, someone with osteoporosis (weakness and brittleness of the bones) cannot have this condition held against them when they suffer a broken bone when struck by another in a car accident.
Generally, while preexisting conditions do not matter with respect to new injuries, defendants and their insurance companies will often claim that an injury is not a new injury, but rather an injury that resulted prior to the accident. Thus when a car crash victim with a bad back complains of an injured back following the accident, the defendants will claim that the current back injury and conditions had nothing to do with the crash, but rather the current back pain is simply ongoing pain.
It therefore is usually important to prove to a jury, often with experts such as physicians and therapists, the change in the condition of a person after the accident compared to before the accident.