How do my pre-med classes relate to practicing medicine: Biomechanics
During the last tour, many pre-medical students mentioned how disconnected they felt from their dreams of becoming a doctor. They questioned how the basic science classes they were trudging through (inorganic chem, orgo, biology, physics) were really related to the knowledge they would soon acquire to be a physician. I am not going to lie, in medical school, we don’t actively use some (or many) of the concepts you learn in the pre-requirements. But, it’s not to say that these things don’t matter. They do; it’s just that they matter in a “background knowledge” sort of way. This all being said, the next set of blog posts will try to relate some of the “mundane and boring” basic science concepts of the pre-reqs with the more interesting, medically relevant pieces of medical school (and actually of the practice of medicine). Some may use straight relationships between the topics, others may go the route of patient-based cases, some may even use scientific articles to present the information. And then there are the wildcard mentors who will do whatever they want. The key is just to keep following and see how the world of basic sciences plays into the world of medicine
In getting it started, I want to present something from my world of interests. At some point in physics, we all saw these free-body diagrams (http://www.google.com/imgres?um=1&hl=en&tbo=d&rls=com.microsoft:en-us&authuser=0&biw=1519&bih=793&tbm=isch&tbnid=R5agSdDdNv4A_M:&imgrefurl=http://www.aplusphysics.com/courses/honors/dynamics/ramps.html&docid=4oqfXPNq_OxzUM&imgurl=http://www.aplusphysics.com/courses/honors/dynamics/images/BoxInclude_June2003.png&w=724&h=527&ei=_dTsULj5LOW80QHOhIGgCw&zoom=1&iact=hc&vpx=335&vpy=265&dur=82&hovh=191&hovw=263&tx=106&ty=128&sig=107112669469462815675&page=2&tbnh=130&tbnw=179&start=32&ndsp=51&ved=1t:429,r:59,s:0,i:271). The basis was always about understanding the different forces at play, including friction, gravity, and the normal force. You learned about changing the surface and how coefficient of friction can change the speed of the object sliding. Sometimes we talked about the world where somehow, this box stayed completely still on the ramp without having anything stopping it (study of statics). BTW, if you haven’t learned these things, you will…
I have a big interest in sports medicine and musculoskeletal injury so physics has always been very intriguing to me. My research involves studying cartilage and how it biologically responds to mechanical stimuli. But I am also interested in biomechanics and how all of this plays a role in human movement (which I frankly think is a very cool and beautiful/ artistic subject). In my Primary Investigator’s lab, he also studies gait and how people walk. In particular, we look at how osteoarthritis, and even joint replacements, can change your movements.
To decrease pain, it is thought that we might be able to “retrain” people the skills of walking to better align their gait so that the joint pain they experience is minimized. To do all of this requires an understanding of the forces at play at a joint of interest (see image http://www.google.com/imgres?um=1&hl=en&tbo=d&rls=com.microsoft:en-us&authuser=0&biw=1519&bih=793&tbm=isch&tbnid=6YC6mO1c2tBllM:&imgrefurl=http://www.sciencedirect.com/science/article/pii/S0303264703001187&docid=Acza8YgIdMUm8M&imgurl=http://ars.els-cdn.com/content/image/1-s2.0-S0303264703001187-gr1.jpg&w=441&h=286&ei=LNfsUJamBNSw0QGoqYDoAg&zoom=1&iact=hc&vpx=172&vpy=136&dur=2212&hovh=181&hovw=279&tx=114&ty=114&sig=107112669469462815675&page=1&tbnh=149&tbnw=230&start=0&ndsp=34&ved=1t:429,r:1,s:0,i:91). The diagram may look complicated but it involves the same basic principles as that block on the ramp. To walk our bones and muscles and soft tissue and neural signaling work in coordination to allow movement. As we take each step, our weight gets distributed differently from foot to foot. Our pelvis even has to “swing” so that we can clear the floor to take the next step. Gait analysis uses force plates, marker systems, multiple cameras, and computers to help analyze how we walk. To me, the application of those simple free body diagrams is much cooler than doing the physics problems where we change the weights or the angle of incline on the ramp. However, without that, we wouldn’t be able to apply it to this awesome area of human movement.
If you’re ever searching for some other practical ways to apply your basic properties of mechanics, here are a couple of resources I enjoy. Search for Sports Science, which used to be it’s own show but now is part of ESPN. Some of my favorite books include “The Physics of Baseball” by Dr. Robert Adair, “Why a Curveball Curves?” by Popular Mechanics, and “The Physics of Football” by Dy. Timothy Gay. And in times of desperation, you can go the route of academic publications and use keywords, like gait, biomechanics, sports medicine, while searching in PubMed. These same concepts about mechanics play a role in developing prosthetic devices for amputees, in better understanding the impacts of hits in football and the relationship with brain injuries (ie concussions), and even in the world of video game design (it’s how they get movement to look so real). So there is real life after basic sciences.