Great Edinburgh Cross Country 2015 Men’s 4k Running Form Analysis

Last weekend was my favorite race of the year, the Great Edinburgh Cross Country 2015, as well as the obligatory cold I always seem to get immediately following it. I’d have to say at this point I have kind of a love-hate relationship with the event for that reason. So my apologies for the week’s wait, but here finally is the first of my own high-speed videos and running form analyses of the events.

The theme that stood out for me across the senior races was the relationship between how people organized their spines and their armswing, and today we’ll look at that in Garrett Heath, Japheth Korir, Dathan Ritzenhein, Asbel Kiprop, and Tom Lancashire in the men’s 4k. I’ll follow up with comments about the men’s 8k and the women’s race next week.

Here’s the official broadcast video of the end of the race. Take a look at the first five finishers: Heath, Korir, Ritzenhein, Kiprop, and Lancashire. Notice that Heath and Ritzenhein move their arms differently from Korir and Kiprop, while Lancashire does yet a third style of movement.

People sometimes describe what Heath and especially Ritz are doing as “flailing,” with the arms swinging vigorously through a fairly large area of space in front of and to the sides of the torso.  On Heath it’s particularly visible from the front, so look as he approaches the finish line and the camera is right in front of him. Just before that, when the camera is above and in front, you can see that his hands are fairly far in front of his chest at the top of their upswing and don’t come quite to his mideline. On Ritz its easier to see altogether that his hands make large eggbeater movements reasonably far from his torso. This is considered not the most efficient style and that’s probably right for a few reasons I’ll get to in a moment.

By contrast, Korir and Kiprop swing their arms in a compact style, keeping their hands close to their torsos, near their chests. This looks more economical, and in my experience working with runners it does make running feel easier and faster.

Lancashire keeps his upper arms close to his sides; it looks like his lats are very active in this. This reduces the size of his armswing and keeps it lower, nearer his waist than either of the other two styles. Chris Derrick, winner of the 8k (which I’ll get to next week) has a similar body type and does a similar thing.

Now take a look at my high-speed (120 fps) video from a different point in the race course.

Compare the upper backs of these five guys as they pass my camera. You’ll see that Heath and Ritz have somewhat rounded upper backs compared to Kiprop and Korir. All four runners lean forward appropriately, but Heath and Ritz are flexing their torsos whereas Korir and Kiprop have very straight upper backs.

The effect of flexing the torso is that it tends to push the hands forward and make the arms flail. Doing this requires actively contracting the abs to pull the sternum down, and when this happens it becomes more difficult to turn the upper body. Yet the legs are still moving, and something needs to counterbalance the action of the lower body or you’ll lose control and fall. With the upper spine and ribcage restricted in their movements, the arms have to do the job of creating a counterbalancing force, so the size of their movement increases. The distance between the hands and the torso is too large because the torso is pulled away from them and the hands are pushed forwards, the feet land a little too far forward due to the flexion of the spine and the fact that the feet tend to land directly under the hands, and the glutes and back muscles are lenthened and in a poor position to work properly.

By contrast, when the back is kept “straight,” meaning all the normal curves of the spine are there more or less as in standing (albeit in a forward lean), the hands can stay close to the body and the thoracic spine and ribcage are able to rotate freely enough to counterbalance the lower body. This is a much smaller movement closer to the center of the body to accomplish the same goal as the flailing armswing did, and so it likely takes less energy to perform. The feet land closer to the center of gravity because the hands are closer to the center of gravity, and the extensors are able to work as needed. The spine is also better able to transmit force from the ground to the head, a critical factor for good running.

Here’s a collage of screenshots of, from left to right, Heath, Ritz, Korir, and Kiprop. Don’t be thrown by Korir’s right arm being so different from the others, he’s on the opposite leg from everyone else.

GEXC 2015 men 4k

Can you see the quite stark difference between the backs of the first two compared to the third and fourth? As a result of having flexed torsos, Heath and Ritz can’t turn their shoulders to carry their swing arms behind them as much or easily as the other two, so their elbows straighten and they push their hands downwards instead of swinging their elbows back. This creates a much larger range of motion for the hands.

In addition, you’ll notice that Heath and Ritz appear to have their stance feet somewhat in front of their pelvises whereas the other two have their bodies farther forward. This appearance is somewhat exaggerated by the angle of the screenshot — we see these two a bit from behind and the other two more directly side-on. Furthermore they’re both a hair earlier in their gait cycles than Korir and Kiprop. Nonetheless, it’s not entirely an illusion; as I said above, flexing your trunk pushes both your head and feet forward, and thus causes runners to “sit back” a little, with the pelvis behind the stance foot in midstance.

Obviously in this race as always, it’s not the best running form that makes the winner — it’s just one of many assets a runner may have. Heath did just fine despite being a bit flexed, winning definitively.

If your coach, friends, or teammates have said something to you about flailing arms, you may have tried to fix them but found it impossible. Instead of focusing on your arms, focus on releasing the excess tension in your abs and chest, mastering a healthy, counter-rotational core action, and bending your elbows enough to keep your hands close to your heart and you’ll find the problem vanishes and your running feels much nicer and faster.

2 thoughts on “Great Edinburgh Cross Country 2015 Men’s 4k Running Form Analysis”

  1. another great post jae! i love discovering more about true economy of running motion – and i for one can say that having started to implement some tweaks to my running form (especially arm swing) that i feel much more efficient in my workouts.


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