How to Use Eccentric/Concentric Contrast to Improve Technique in Any Movement.
Hey everyone. I wanted to share this very useful strategy for structuring technique work. This is something I’ve utilized myself for 4-5 years in a broad range of movements and disciplines. The strategy is based on a very simple observation and principle regarding concentric and eccentric phases of movements.
Ever notice that when movements are intense, they don’t always go they way we plan? Joints end up in angles we didn’t intend; muscles that aren’t really meant to do the job end up doing the job; muscles that are supposed to do the job aren’t active enough; knees wobble, hips shift and collapse, shoulders rotate, spines flex or extend excessively, etc. These compensatory patterns are an attempt to execute the movement at any cost. And sometimes that “cost” is efficiency, efficacy, and long-term sustainability.
What is “good” technique?
It’s not an easy question to answer: what is the ideal technique in a given movement? There are many, many factors that need to be considered. Many of these factors are specific to the individual. And there’s no way I can hope to address all of those here. Instead you can see the following as one piece of a multi-dimensional puzzle.
But a working definition of ideal technique might be something like, “whatever execution allows for maximal force production or desired stimulus for the individual long-term, factoring for sufficient and sustainable practice.” The long-term part is important, because technical adjustments sometimes require taking a step backward. The adjustments can feel awkward, and take getting used to. But long-term, the right adjustments to technique result in better efficiency, force production, or desired stimulus. The sufficient and sustainable part is also important, because without consistency over a long time, we can’t hope to maximize progress.
So the following strategy is meant to help individuals move closer to a technique that naturally suits them in a given movement, and serves their progression in all of the ways listed above.
Your technique in a given movement will likely be “better” during the eccentric phase of a movement than the concentric phase. Why? Simply put, the eccentric is easier. You can bear far more load during the eccentric phase of the movement. And so the need to compensate for various weaknesses will be less. By studying the eccentric phase we gain access to a picture of what the concentric path of a given movement would look like if our weaknesses didn't have so much influence.
Defining some terms
For those of you who aren't familiar with this terminology, the ”eccentric” phase of a movement is when your working muscle groups are generating force while lengthening. Whereas during the concentric phase the working muscle groups are generating force while shortening. To keep it simple, imagine a biceps dumbbell curl. As you lower the dumbbell, the working muscles (biceps) lengthen; this is the eccentric. As you lift the dumbbell, the working muscles shorten; this is the concentric. In a loaded barbell squat, the working muscles (though there are many) are predominately quadriceps and gluteus muscles. As you lower into the bottom of the squat, these muscles produce force while they lengthen, to slow you down; this is the eccentric. As you stand up, they produce force while they shorten; this is the concentric.
The Strategy
The following is just an example of how to use this insight about eccentric vs. concentric technique. I use a high bar back squat here, but you can really apply this to almost any movement. The first and most important observation is that my eccentric looks different from my concentric. This is not necessarily a problem. And to a degree, there will always be a difference—especially as the intensity climbs. But the idea is to close the gap as much as possible, and use the eccentric as a guide to better concentric technique.
Identify your “sticking point” or where you tend to get stuck, slow down, or technique breaks down. This weakest point in the strength curve will typically show itself and be easier to notice when the intensity is higher. You find your sticking point by building up to a manageable weight/intensity that challenges you.
Record a video of 1-2 reps in the movement, from an angle that shows the pattern you want to address.
Take one screenshot of your video at your sticking point during the eccentric, and one more screenshot at the exact same place in the concentric. It might take a few tries to get the screenshot in the right place.
Compare. Toggle back and forth between the two screenshots and notice the difference in position. On iPhone, for example, you can use the camera roll at the bottom of the screen by sliding it left and right. This is shown in the videos below. I’ve just made a screen recording of toggling back and forth between the two screenshots.
Once you notice the key differences in position, on your next set choose one technique to address. Try to make the position at your sticking point on the concentric match your position at the same point in the eccentric. I’ll give you examples of this in the squat videos I recorded below. One at a time. If you try to make multiple corrections simultaneously, it will dilute your focus and likely you’ll miss all of them.
Once you’ve successfully executed the correction, or closed the difference between eccentric and concentric positions at the sticking point, keep it in the back of your mind and move on to one more technical correction.
Be patient. Don’t expect to get it the first, second, or even fifth try. Just keep reviewing the videos, taking screenshots, comparing, and making a singularly focused effort. You are not where you think you “should” be. You are where you are. That is the reality. Face it, and do the work.
Don’t go too high in intensity, or you won’t be able to make the adjustments effectively. But don’t make it too easy either, or you won’t be challenged to apply the technique under specific circumstances when the pressure to compensate is present. Find the sweet spot.
Example application
Below are some examples of how I applied this strategy to my high bar back squat. After watching some videos of my squats at higher intensities, I noticed that my torso tended to lean forward, my hips and knees moved backward, and my knees buckled inward at the sticking point in the concentric when compared to the sticking in the eccentric. These are not all of the sets, but some examples of key turning points. I’m working with 150kg here, as it challenges me enough to bring out compensation patterns, but it is not so heavy that I can’t effectively make adjustments. For me, on this day, 150kg was the sweet spot.
1. Key observation: hips and knees moving back in space, and torso leaning forward at sticking point. Intention for next sets: drive knees forward over toes at sticking point.
2. Successfully corrected the hip and knee position. But now femurs are internally rotating (knees collapsing inward). Intention for next sets: use glutes to drive knees outward during concentric.
3. Successfully corrected femur rotation (knees collapsing inward), but torso lean returned. Still better than first set, and hip position is better, but not satisfactory. Intention for next sets: chest up, knees out and forward over toes at sticking point.
4. Knee position still satisfactory, but hips shifted back and torso leaned again. Failed to focus on applying intention. This is important to show you: not every set will be a successful application of your technical intention. Sometimes focus will stray. Take note and go again.
5. Satisfactory application of both technical adjustments. Knees, hips, and torso in a much better position at the sticking point. Concentric more closely resembles eccentric.
Finish on a good note
In the words of Chris Voss, “The last impression is the lasting impression.” Try to end your technique session on a note of success, even if it’s a small success. Even what seems like a small adjustment toward better technique, when played out over hundreds or thousands of repetitions, is actually very significant. These kinds of adjustments when applied consistently can completely change the trajectory of performance over years. Perhaps more importantly, these kinds of technical adjustments can make movements feel a whole lot better. And that’s priceless. So resist the urge to keep going and going to correct every little thing you notice. Notice the victories when you achieve them, remember to smile at them, and finish on a good note.
If you don’t already have a tripod for your phone, they make everything a lot easier in terms of getting the right angles to evaluate your technique. They don’t need to be fancy. You can typically find them for less than $10 online.
Remember that good technique is a road toward moving better, feeling better, and getting more joy and longevity out of your physical practice. Technique work is not an excuse to beat yourself up for being a shitty person. Notice when you try to use technique work to “fix” yourself. There’s nothing to fix; only opportunities and possibilities to explore.
Devin