How exactly do we run?
It’s a question worth asking for runners, coaches, and running gait theorists. Some would argue that gravity propels us forward. In fact, I used to buy into this model. It seemed to make sense- lean forward so you’ll off-balance and let gravity pull you down, which resulted in forward movement.
Then I started to read about running gait from researchers that actually study gait in labs. The gravity theory didn’t hold up to empirical scrutiny. About the same time, I started interacting with some of the “natural” running theorists. They had a much different take on how we run. The most influential have been people like Steve Magness, Mark Cucuzzella, Jay Dicharry, and Pete Larson. Their ideas of running gait were far different. More importantly, their analysis was based on actual observation using scientific methodology.
The following is a re-post from a discussion we’re having over at the Barefoot Runners Society. We’re debating how we run with an emphasis on the claim that running is a controlled fall. Here’s a summary of my counter-point. Note: the goal of the post isn’t a detailed biomechanical or physics explanation of running gait; it is part of a colloquial discussion.
Role of a lean in running
Regarding a workable model of gait- The spring model works pretty well. Mark C. uses an pogo stick as an analogy. This is how he describes the need to lean- it changes the vector, which results in forward motion.
For example, if you bounce on a pogo stick and remain perfectly vertical, you go up and down. If you lean slightly forward (or any direction), you bounce that way.
Likewise, if you stand perfectly vertical and run, you run in place. If you lean slightly forward, you move slightly forward. The more you lean, the more horizontal movement is generated.
Role of muscles in running
This model only accounts for the energy return (“springiness”) generated from the return of energy stored in soft tissues. It doesn’t account for the other factor in forward propulsion- muscle contractions.
It is possible to run forward by standing perfectly vertical. You can run quite fast, in fact. Why? Muscles generate most of the energy required to run.
Role of gravity
Gravity does play a role in running, but not as a propulsive force. It’s a force that must be overcome, along with drag. A simple diagram of pelvis position can explain what’s going on:
This is the concept Curb and I have discussed. At mid-stance, the hips are at the lowest position of the gait cycle (note the black dot below the line). As we toe off (NOT a good term, IMHO), the hips move vertically to a high point during the aerial phase. The only “falling” that occurs is on the downward arc immediately before touch down.
If we were continually falling forward, mid-stance would be the point where our hips were at the highest point. The hips would then lower as we toe off (due to falling), would reach the lowest point at the middle of the aerial phase, then begin an upward arc at touch down.
The Unspoken Question
The Pose and Chi crowd seem to neglect a critical part of their theory. If you’re falling, you need to expend energy to get back to a point where you can fall again. If we really were falling and we saw the movement pattern that would be the opposite of the above diagram, the point from touch down to mid-stance would require muscular energy to return to mid-stance so we could fall again.That energy expenditure would cancel out any possible gain from falling, plus more. To date, Ken S. is the only Pose coach that has addressed this issue… which is the reason I have so much respect for his ideas.
Why it’s important to study gait
We don’t necessarily need to study running gait to be able to teach people to run better. However, knowing all the underlying theories is a HUGE benefit to diagnosing problems or mastering a variety of teaching methods. I used to teach high school psychology. It was immensely helpful to have a strong background in the topic. I also taught history and didn’t have a strong background. I was a great psychology teacher and a terrible history teacher.
It’s also important to think critically about our own beliefs. Read the first edition of my book, then read some of my recent blog posts. I have different opinions on a TON of topics because I question my own beliefs regularly. While I really believe my above comments are the most accurate current model of running gait, I’m always looking for better models and will ditch this if something better comes along. I’m a science dork at heart, and that comes out in my inherent skepticism.
Folk knowledge versus science
Bare Lee made a comment awhile ago about the difference between folk wisdom and science. As barefoot runners, we tend to rely on folk wisdom, or tips and explanations that get us to more or less do the correct movements but have no basis in science. Examples would be:
- Lift your feet
- Bend your knees
- Pull your feet up
- lean forward at the ankles
- Run with a cadence of 180 or 180+
- land pancake flat
- feet land under the center of mass (gravity, hips… whatever)
- stand up straight
This also includes explanations of movement like “running is a controlled fall.” It also includes claims like barefoot running reduces injuries, makes you faster, more efficient, etc. All of these ideas aren’t grounded in empiricism or are obviously inaccurate, but are effective as teaching methods because they work for some people some of the time.
However, we can’t confuse folk wisdom for science. Science is a controlled method of inquiry, and none of the above claims has been firmly confirmed via science. As such, it’s important to figure out exactly how we run… or even if there’s a right way to run. Many topics can be added to that list: what are the role of shoes? Is there a right way to teach people to run? If so, what is the most effective method? Is there a way to reduce injuries? If so, is it universal?
Folk wisdom is an adequate way to answer the questions in the absence of empirical research, but it shouldn’t be a replacement.
So, anyone care to add to the discussion? Feel free to comment. Since this topic tends to evoke emotion, I’ll delete any comment that isn’t civil in tone.