What does "contributory negligence" mean and why is that important in a Virginia brain injury case?

In another Frequently Asked Question, I explained the meaning of "negligence" and why it is important in Virginia brain injury cases and all other personal injury cases in Virginia.  "Contributory negligence" means the same thing as "negligence."  The only difference is that, when lawyers speak of contributory negligence, we are referring to any negligence committed by the injured person (the plaintiff) that "contributed" to the injury.  Hence, the word "contributory" is inserted in front of "negligence." 

Why is this distinction important?  It is important because of the common law in Virginia.  Virginia is one of only two states (I believe) that still adheres to the old rule that, if an injured person's own negligence contributed to his or her own injury, then the person is completely barred from recovering compensation from the defendant.  So, for example, if a defendant store was negligent in maintaining its store by leaving a tripping hazard in a walk way, a person injured by that negligence would be completely barred from recovering money from the defendant if the injured person was also negligent in failing to watch where they were walking.  This is a pretty harsh rule, particularly in cases in which the injured person was only slightly negligent.  That, unfortunately, does not matter.  Most other states adhere to some sort of "comparative" negligence rule.  In such states, the jury can take into consideration the degree of negligence attributable to each party and take that into consideration when awarding compensation to the injured person.