Shape vs. Position: A New Way to Look at Movement
Understanding the difference between these two similar ideas may be the secret to unlocking a better approach to program design.
Defining the Difference
The more I understand movement, the more complex my view of the involved systems, signals, and stresses becomes. When you're trying to understand all the myriad ways the body experiences stress (training), things can get pretty granular pretty quickly, and there's a danger of losing the forest for the trees. For that reason, I find approaches that let me see things in a big-picture manner increasingly valuable.
Comparing and evaluating exercises through the dual lenses of shape and position has helped inform how I look at programming, progression, skill acquisition and more. The idea is a simple one—and the definitions my own—but its impact on your training will be far-reaching. We'll get into more detail in a moment, but for now, think of shape, position, and movement as three points on a spectrum:
Shape —> Position —> Movement
As I move from left to right my view gets more complex and inclusive, with "movement" representing as complete a picture of an exercise as you can manage.
Most of us started to learn shapes when we were still learning to walk, and this isn't much more complicated. Shape is the simplest of the three concepts—what shape does the skeleton take? What joint angles are involved, and how are the limbs and trunk arranged? It's the anatomical equivalent of recognizing that a tire and a donut are both circles.
Shapes reflect strategies—they're a literal articulation of how our system is solving the movement problem in front of it—and as such, there's bound to be some repetition. What worked once will likely work again. We'll get into application of these ideas later, and that idea will prove critical to putting shapes to work for you and your clients.
Shapes reflect strategies—they're a literal articulation of how our body is solving the movement problem in front of it.
If shape reflects strategy, then position involves outcomes, as it begins to consider the effects of environment, both internal and external. Position is where shape meets force, and where we start to examine the differences between similar shapes. Sure, the tire and the donut are both circles, but they're still very different iterations of the same shape.
The image above shows three nearly identical shapes and three very different patterns; while the skeleton and its attached musculature are in the same position, the forces being created by and applied to those structures could hardly be more different. From the physical to the neurological, the experience of these three positions is very different.
Position sits between shape and movement—it considers the forces and vectors being applied to the body's systems but not their speed or synchronicity. They're static rather than dynamic expressions of force; snapshots rather than movies. On its own, it's hard to tell whether the picture in the upper right shows a dead hang or a pull up variation, and for the purposes of position, we're not really concerned with the difference.
Finally, in my mind, position occupies multiple points on our spectrum; as we'll see, specificity can be dialed up or down by making slight adjustments to position, and it's important not to confuse this by imagining some Platonic ideal of what position represents.
(Why) Does It Matter?
Being able to toggle your point of view back and forth between shape and position can help you diagnose why a movement falls apart, create better progressions to help prevent movement faults, and find shortcuts to to get you and your clients moving better in less time. By understanding how shape and position complement one another, we can fine-tune the specificity of a drill, beginning broadly and honing in as appropriate.
The image below shows a classic wall drill for improving acceleration mechanics, and a screenshot of my second stride out of the "blocks". The similarities in shape are fairly obvious, and while the positions are different, the use of the wall (or tree in this case) introduces some similar forces to the drill.
By using shape as a constant and position as a progression, I can design (or evaluate) an exercise progression meant to improve acceleration.
March with Medicine Ball Overhead
A Skip with Medicine Ball Overhead
Static Single Leg Wall Drill
Dynamic Single Leg Wall Drill—Single Switch
Dynamic Single Leg Wall Drill—Dual Switch
Dynamic Single Leg Wall Drill—Rapid Fire Switch
If you're familiar with these drills then it should be fairly apparent that the shapes involved change only slightly, while the forces—and hence the positions—edge closer and closer to the target activity of acceleration. This is progression in a nutshell; not just harder, but moving ever closer to a goal.
Big Picture (Change Header)
Movement is a collection of repetitive, sequential positions, which are themselves an expression of shapes under the influence of load. Understanding position, then, really comes down to how we think about load.
A number of years ago I read a book called Move Your DNA, by Katy Bowman, M.S. In it, she argues for a diverse "diet" of movement, and lays out a fairly compelling scientific case for our need to experience not just more movement but more variety of movement. One line has stayed with me since then:
"The twenty-pound weight is not the load. The load is the experience created by carrying it."
Katy Bowman, M.S., Move Your DNA
Put into the concrete terms of the weight room, we all recognize that where we load an athlete has a tremendous impact on the resulting movement—try keeping your ribcage stacked over your hips during a low bar back squat. It should be a relatively small mental step, then, to separate shape from position, and to consider both when prescribing an exercise. Knowing the shapes and positions an athlete owns and the ones they're still working on, as well as how to manipulate both to change the demands of the movement, gives you a clear, logical way to look at programming, particularly our progression and regression strategies. By leveraging the body's tendency to adopt similar fundamental shapes for a variety of movements we can build programs that echo this repetition, and give both coach and client a physical context for the position.