Poor Construction: The Human Knee

566172_1.jpgAs Penn State students, I assume that most of you were watching Saturday's football game against Indiana. And if you're a true Penn State fan, you were probably just as heartbroken as I was when Michael Mauti went down with the ultimately season ending injury to his knee. Mauti's injury brought the question to my mind: why is the human knee so poorly constructed?

Everybody knows someone who has some sort of problem with his or her knees. The cause of such widespread problems can be attributed to the anatomy of the human knee. Basically, our knees are two bones held together by three bands of ligaments (the ACL, PCL, and MCL). If you're thinking that this does not sound like the most stable of designs for the joints which support the majority of the weight of the human body, you'd be correct. We know that it's a poor design, but the question is, why are our knees designed like this and why hasn't evolution taken care of this? Not much can really be found to answer this question, especially written in terms that us regular people can understand. This Wikipedia article I found discussing the evolution of the human skeleton to accommodate bipedalism states that knee joints became larger as humans began to walk upright, in order to support more weight. However, the issue as to why the ligaments have not become better protected is not so clear. One reason that I believe that knee ligaments have not become better protected through human evolution is because of medical technology. In today's advanced world, the need for humans to evolve to adapt to their environments in order to survive is not nearly as urgent as it was say, hundreds of thousands and millions of years ago. Millions of years ago, those who had stronger knee ligaments would be the ones to survive and pass on genes of these strong ligaments because then, survival depended on mobility. In today's world, it seems that we have halted the process of evolution, which we know takes millions of years, because the need to adapt for survival no longer exists. Also, perhaps the human knee joint is not better protected because in becoming so, human mobility might suffer, causing evolution to maybe pick and choose what seems to be most beneficial. This seems to be a complicated issue that seems like it would take a lot of research to figure out. Has mobility increased vulnerability of knees, or in reverse causation has a more vulnerable design increased mobility? And is it possible that with today's technology, we are stopping the survival of the fittest process and evolution of the human species?


Hey Lauren I think that your blog post makes an interesting statement because injuries occur very often in sports and not everyone knows why. I agree with you that it seems as though the two bands being held together by the three ligaments is an unstable design for our knee but I think that we should remember that the human body can’t be the strongest it can be without a proper diet. Perhaps there may have been a third variable that caused Michael Mauti to hurt his knee; that being his diet.

I think that we should remember that there is a reason why certain diets help strengthen our bodies. Certain foods have the nutrients that we need to make our body stronger and without those foods our bodies are obviously more vulnerable to injury. The structure of the human body may not be the only reason why Mauti got injured but his diet may be the reason. Even though Penn State’s football players are most likely on a regimen, it is possible that Mauti lacked a certain type of nutrients that he needed which made him more vulnerable to get hurt.

Even though I didn't realize it until you said it, everyone does know at least one person with a knee injury or issue. But, more specifically, I feel as though anyone I know with one small problem with their knee, eventually has a million other problems with their knee, too. Foe example, my friend dislocated her knee one time. Then, she dislocated it four more times. Ultimately, she needed surgery. Are some people's knees more susceptible to injury than others? Why is it that an individual with a knee problem usually continues to have that problem or a variety of other knee problems for life?

Also, one of the biggest body health issues I feel like I notice in the elderly is also in their knees. You've explained why our knees are initially weak, however why is it that they continue to grow weaker and are usually one of the first things to go as we age? What is it about our knees that cause these specific problems as we grow older more so than other parts of the body? Is there a different reason than why elderly have knee problems as opposed to younger people? This article, http://www.livestrong.com/article/132723-causes-knee-problems-elderly/, explains various problems the elderly has with their knees and possible explanations, however it does not really explain the question I've been wondering: why the elderly and why knees specifically?

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