Tuesday, July 26, 2011

Running Form Study

A few weeks back I participated in a study at UNC Chapel Hill entitled "A Comparison of Lower Extremity Joint Work and Initial Loading Rates Among Four Different Running Styles". The study is attempting to compare the mechanics of running for the following styles:

  1. Traditional running shoe wearing heel striker
  2. Barefoot or minimalist runner
  3. A POSE runner
  4. A Chi runner
I personally fall into category number 2. 

The experience of participating in the study was very interesting. After arriving at the human movement lab at UNC Chapel Hill, I changed into some running clothes and met with Don Goss, the PhD candidate running the study. The next 30 minutes or so was spent attaching various reflective motion tags to my hips, knees, ankles and feet. Then I stepped onto a giant double belted treadmill surrounded by high speed sensors which would track the reflective motion sensors attached to my body. After an initial calibration we discovered that some of the Asics logos on my shirt were reflective and were being registered by the motion sensors. We used some tape to cover the few reflective patches of clothing on my running shirt, which were throwing off the motion sensors, and then the sensors successfully locked onto the true reflectors. 

Once successfully locked onto the sensors, Don actually removed about half of the sensors and allowed the software to interpolate between the remaining sensors. I ran on the treadmill at a comfortable pace (I think around 10 min/mile) for about 5 minutes, first with a foot on each belt, then both feet on the left belt, and finally both feet on the right belt. Don took several 3 second "samples" from the sensors. The motion sensors could capture several thousand frames per second, but Don indicated that this caused a serious data overload (processing the data took hours). So the motion sensors had been dialed down to capture only about 240 frames per second. The force plates in the treadmill captured 1200 samples per second.

All of this data was visually represented in various graphs and tables on the capture computer, but the cool part was the animation that was generated by the data. Here's a sample video of the running form data captured from my session:

From the video, it's fairly obvious that I'm a mid-foot striker. Which is good, because that's what I've been trying to become for the past year. There were some occasions where I had a very mild heel strike on my right foot, but the peak impact forces never varied much when that happened and were always approximately equal to two times my body weight.

Overall, this was a very cool experience and I recommend anyone who is in the North Carolina region to volunteer for the study if possible. Don still needs some dedicated Chi and POSE runners for the study, but he may also still be taking data for other styles. I've listed Don's contact information below if you are interested in participating.

PhD Candidate, Biomechanics
University of North Carolina at Chapel Hill