CrossFit Athletic Group

Which object would you rather do a heavy clean and jerk with? This one…

or this one?

It’s much easier to move an object that moves as one piece. More moving pieces = more variables, and you have to work much harder to successfully move the entire object. The force you apply to it dissipates as is passes through each moving segment. This presents a problem when you have to perform multiple reps, use a heavier load, or move faster.

This rule also applies to our own body. It's the "One Joint Rule," as Kelly calls it, that dictates our body's ability to generate and withstand force. The One Joint Rule is most often applied to a deadlift. We know that the more your back moves, the more potential you have for injury. That's because the huge force that your body has to overcome is dissipated throughout each spinal segment that moves. It is essential to keep a 100% rigid spine and only hinge at the hips, which is the "one joint" allowed to move in this case.

The One Joint Rule is just as important when you're unweighting. More variables = more problems. When you “unweight” with your arms bent and let them flop around like noodles, or your knees stay bent, or your belly isn’t tight, you are creating the same problems within your body. 

Here’s Katie Kav demonstrating noodle arm syndrome at the 9 AM on Friday:

And here’s fellow 9 AM’er Sydney keeping her arms straight.

I didn't take the picture at the right time for Sydney. This picture was taken right before she fully unweighted. The picture of Katie was taken right as she unweighted, and her arms were bent before her shoulders began to rise up. This is a common fault for people who have trouble unweighting properly. Not only is Sydney able to unweight her shoulders more easily, but she is able to keep a good shoulder position that will translate to a better receiving position for any lift.

When you have body weight, you need to have as few moving pieces as possible.