RANGE OF MOTION

What is range of motion in running? Is it equivalent to stride length? These questions appear again and again on our running forum. How are we supposed to understand these terms and how are they related with our running technique? Behind these questions stand our past experience and understanding that fast running is somehow related with longer stride length or bigger range of motion. We consider these terms as something similar, almost synonymous, though have some doubtful feeling that it may not be so. But because we use them freely and interchangeably in our everyday life and nobody argues about their meaning, we just get accustomed to such usage. After that our confusion becomes accepted as normal, bringing a logical question: "What is there to discuss?"

But a proper understanding and use of terminology has consequences far beyond of just "innocent" use of words. Our terminology is shaping our life and forming our actions. We are doing everything according to our accepted terminology, which governs our thoughts, desires and actions. If we understand terminology wrong, then our actions may be wrong, as well. Therefore, we need to look at our terminology seriously and establish the meanings behind the terms according to mechanical or biomechanical reality of movement, which is in our case running.

The stride length in biomechanics of running is a distance between the points of the same foot on the ground (support) in two consecutive steps, from the left foot to the right and again to the left. This is a bit confusing, but it is how scientists decided to measure stride length. I prefer to work with a step length - the distance between the points of support on the left and right foot, but this is not a big deal at the end of the day.

The range of motion in biomechanics and anatomy is an ability to bend in our joints. The bigger these angles of bending, the more the range of motion is.

As we see neither one of these terms match each other. These parameters, factors, elements just have different meaning, purpose and nature in running. The fact that they are both elements of running doesn't mean that they are the same. Nevertheless we are using them as similar notions. I wouldn't pay attention to this mistake of use, if it wouldn't have so much negative consequence to our running technique and quality of teaching it. The major problem with this confusion is that it leads to the wrong actions and after that to excessive muscular efforts, which inevitably bring athletes/runners to injuries. How does it happen?

From the Pose Method point of view these parameters have different references and play different roles in running technique. And what is more important, they are byproducts of more important elements of running technique. In the hierarchy of running technique elements stride length and range of motion are following after gravity use/falling, change of support/pulling and muscular efforts. Everything and each element of running technique is recruited by a major, leading factor of running - gravity/falling.

The rate of falling (degree of the body leaning forward) is a regulator and developer of our speed, recruiting our step cadence and muscular efforts. After the speed goes up, our body (the General Center of Mass) starts traveling from one support to another longer. And because of the increasing speed and stride cadence our muscle efforts increase as well in order to fit with the first parameters. By the same token, it's the increasing momentum of our limbs (legs), which moves them apart, bent more, i.e., develops our range of motion. So the more we fall, the faster our speed and stride cadence are. As a result of increased speed the stride length increases as well. Just so, and not vice versa. Furthermore, it involves more muscular efforts and increases momentum of our moving limbs, which, as a consequence, develops the range of motion.

As we see from this logic, all these elements are interrelated and interdependent parts of the system, which we call running, where the major element in hierarchy (gravity) "requires" a specific amount of their involvement in movement. This logic clearly "advises" us to not interfere in these relationships with our concerns about our stride length, range of motion, etc. Our role should be limited to being a moderator between falling/gravity and pulling, and not allowing ourselves to do anything beyond these actions, while letting our body decide how much effort should be involved. In layman terms it means to keep our attention/focus on pulling the feet from the ground while falling and not worrying about the rest.

Dr.Romanov