Functional Movement for Circus: why the little things matter

[UPDATED] Originally, for this post I dove straight into my rigging analogy. In this minor update, I’d like to start with the end in mind: this is a post about the value of movement screening and assessment as a strategy for mitigating future injuries and for improving how you perform in your circus-discipline(s)-of-choice.

There are basically two reasons for looking more closely at how your body is moving:

  1. It provides an opportunity to take action proactively and address those little things that could turn into injuries down the road.
  2. It provides an opportunity to improve how your body performs physically, so that you can become stronger and more mobile.

The trick, of course, is that if you don’t feel any obvious “little things” in your body and you’re not in pain, then it can be challenging to see the value in a movement screen.

And, if you’re already doing “conditioning” things and you’re feeling pretty strong, then I can also understand why you might be inclined to think “if it ain’t broke, why try to fix it?

This is where my analogy comes in…

Let’s talk about rigging. (This will begin to make sense shortly. Bear with me).

Consider the following example.

Actually, wait: please, for the love of common sense, please note that nothing you read here should in any way be construed as “rigging advice”. I’m using rigging as an analogy. There are much smarter people you should to ask if you want rigging advice.

Moving on.

Consider the following rigging example:

Here’s what we know

This is a shackle.

By 魔私利戸 – Own work, CC BY-SA 3.0,

They are generally “U”-shaped with a pin that connects the two ends of the “U”.

A bunch of really smart people with really cool toys tested this shackle design over and over again and they confirmed for us that shackles are strongest when they are loaded like this:

I’ve added an arrow to indicate how the line of force (the force from the load) travels through the shackle.

The key thing to note here is that there is just one thing rigged to the screw pin.

In our rigging example, the way the shackle is being loaded means the line of force (basically a straight line from the anchor point to the ground) goes this way:

Notice the line of force does not travel straight through the green cable or the red anchor bolt.

Whereas the equipment in this system goes this way:

Each “corner” in this line represents a stress point.

With this configuration of equipment, adding load to the system creates a torque on the pin of the shackle. This creates a focused stress point within the system: meaning that a part of the shackle is subjected to stresses in a direction that it may not necessarily handle well.

We know how strong the shackle is when loaded optimally. It’s harder to say how strong the shackle is when it’s loaded this way. All we know for sure is that it’s less strong. (Probably a lot less strong).

Now let’s add details to our example:

Sometimes, it’s just a static load. Weight that doesn’t move much.

Other times, the system undergoes dynamic shock loads—often the result of sudden movement. In these cases, force is added to the system very quickly.

Shock loads can add large amounts of force to the system in a very, very short amount of time. They tend to be sudden spikes in load on a system, which is, you know, like a shock to the system.

Assuming this system were rigged correctly, we would be able to make sure that the loading of the system never exceeded its capacity.

Since it’s not rigged correctly, it’s hard to say. (I’m sure there are some physics wizards out there who could easily and happily calculate the angle at which the shackle sits relative to the imposed load and then calculate by how much the capacity of the system is reduced. I briefly considered doing that math and realized it is beyond my current level of ability. What we know for sure is that the breaking strength of the shackle is reduced.

Depending on what exactly the dynamic and static loads are, it might just be fine. Possibly. You know, or not.

(It’s also possible here that the pin could snap in half).

I imagine that this might be the part of the story where the riggers in the audience have their heads explode at the thought of calling a rigging configuration like this “probably fine”.

I imagine also that by now, the parallels of my analogy to the human body have become transparent and clear.

The human body—your body—is absolutely amazing in its capacity for adaptation.

This is one of my favorite things in the whole world to marvel at.

Your body is, among its other wondrous qualities, remarkably good at being efficient.

Let’s consider, say, for example, overhead shoulder (flexion) range of motion. Both Theresa and I have mentioned numerous times in the past that it’s important to have full, 180-degrees of overhead range of motion.

However, what matters more is not whether your body can get your arms all the way overhead, but how you get your arms overhead.

If your lats or posterior rotator cuff have too much tone (which you could interpret to mean they are “tight”), then when it comes time to hang from something, your body find a way to let you do that (probably by extending your low back—and compromising core engagement and increasing the stress on your low back).

Something we see all the time is that folks don’t move their shoulder blades very well when they move their arms overhead. In the name of efficiency, the body usually adapts to this by stretching out the joint capsule to allow more movement at the glenohumeral joint. This may result in a less stable shoulder joint, but the arm still gets all the way over head–which was your body’s goal.

My point here is that, using this example, “getting your arms all the way overhead” is similar to saying that whatever was on the other of that cable is “rigged”. In both cases, it’s done…it’s just not optimal.

And everything will probably maybe possibly be fine.

Until such time as it’s not.

Here’s what we know:

  • Subjecting your body to loads in sub-optimal joint positions will likely create a focused stress point (or points) within the joint. Part (or parts) of the joint is (are) subjected to stresses in a direction that it may not necessarily handle well.

Let’s use my shoulder to illustrate.

This is a photo of the first time I hung from a bar after my first shoulder surgery in 2010. As you can see, I was able to get my arms sufficiently “overhead” to allow me to hang (efficient) even though I did not have full overhead range of motion (which would be optimal).

While the line of gravity should be pretty clear (it’s straight down from the cables), the path that the force had to travel through my body reveals multiple stress points.

For those who don’t know, my surgeon unwittingly made my shoulder too tight and it was never going to have full range of motion again anyway. I just didn’t know that when this photo was taken.

Those ‘stress points’ may—or may not—lead to injury one day.

Similarly, your body will probably end up recruiting ‘helper’ muscles to do work that they shouldn’t really be doing. Usually because other muscles need to be stronger. This extra stress on these muscles is just that: extra stress that takes away from the main job these muscles were supposed to be doing…which may—or may not—lead to injury one day.

If you found yourself looking at the rigging example and thinking “I don’t think I want to wait and see what happens…I’d rather make the set-up better”, then you can probably see why it is that I’m such a fan of movement screening—and more specifically, the work that follows the movement screen.

(It’s no coincidence that I am also a big fan of thinking in terms of the long game.)

Doing a movement screen provides an opportunity for you to learn about how your body is moving now and, where necessary, take steps to optimize how you move. And there are two main reasons for doing so:

  1. Reducing the likelihood and/or severity of future injury. (Notice I didn’t say “prevention”).
  2. Improving physical performance.

Those seem like two pretty solid reasons to me, but again, I’m biased.

From here, we move on to part two (next time) where I’ll go over the two key steps involved in optimizing movement.

Until then, thanks for reading.