Posterior Oblique Sling Enhancing Swimming Performance, Part II

by SwimSwam 6

February 26th, 2018 Lifestyle, Training

Courtesy of Jukka Shemeikka

Part one was mainly an introduction to Posterior Oblique Sling (POS) in relations to swimming performance. In part two I will dive deeper into the concept of POS exercise for swimmers. If you didn’t read the first part, I highly recommend that you do before reading part two. You can find the first part Here.


Part I raised some questions, so to have a full understanding, I will try to offer explanations on some of the terms used in the original text. For further information, please do searches from a nearby library or the internet. If not found, then contact the author.

Hip driven freestyle development circle

Connection points – All competitive strokes have a different amount of connection points. In long axis strokes, there is also a difference in between sprint and distance techniques. In hip-driven freestyle, there is S total of four connection points consisting of each four limbs. The more connection point’s swimmer is able to use, the smaller the frontal surface will be and less drag is produced. Connection happens thru functional lines, so more muscle groups are involved, and optimal load distribution is possible.   

Functional lines – Muscle chains formed by fascia. There is total of eight lines including Frontline, Backline and Spiral line.

Optimal load distribution – Using the maximal number of muscles to produce propulsion with stroke cycle. Case example hip-driven freestyle: Instead of trying to achieve propulsion just by pushing water backward with the arm, focus on the timing and initiate the arm stroke by kicking up with opposite side leg when the arm reaches catch position. In this way, it is possible to use multiple muscles, divide the load more equally, and postpone fatigue.

Individualization – what and when?

For every style of freestyle, there is a reasoning. If you try to swim technically the same as Gregorio Paltrinieri, Connor Jaeger or Katie Ledecky, you’ll understand why they have ended up with their technique. On the base level, their technique is the same, even though they have unique features. All three of them utilize three-point connection freestyle technique, but only for the other side. Interesting about Katie’s technique is that she was able to advance from London to Rio by adding those connections to both sides in 800 fr.

To be able to perform at the best possible level, we need to have qualities like activating functional lines and certain muscles on those lines. When we don’t possess these qualities, it is not possible to develop swimming technique to the highest level. We have a tendency to use individualization as an excuse at the point where we run out of qualities. Still, there’s no escaping the fact that most of the time our need’s for individualization comes from the failures in our training. As coaches, we can choose the way we go about it. We can automatically individualize the swim technique for each swimmer, or we can try to teach as many qualities as possible with training, trying to achieve the most efficient way of movement.

Let’s use lateral bending as an example. In some cases, it has been reported that lateral bending occurring in long axis strokes is natural and efficient way of performing technique. This can be true, but depending on the case. If an athlete doesn’t possess all the qualities needed, then this is true because he/she cannot connect the body in a way, that lateral control may occur. This could be used with athletes, that might have trouble learning the usage of all functional lines. When we start developing athletes at a young age, we have high possibility to affect this situation. If the athlete learns to use his body with natural movement, then his lateral control is better because of all the connection points being involved, resulting in a higher-level technique and better performance.

I think that there is one sentence that describes this perfectly, and it goes something like this:

“We have to manage the complexity of coaching our youth, to be able to simplify in high-performance phase”


Using the POS exercise, especially with the different level of swimmers has thought me, that it can really point out the existence of important qualities reflecting both freestyle and backstroke performances. The important qualities in essential functional lines for long axis strokes are glute activation, core activation and scapula control. One of our current high-performance development project at Olympic Training Center Rovaniemi has been Performance Screen for swimmers. The aim of this tool has been a set of simple land-based tests, which can very clearly show the existence of the essential qualities. None of the scapula control tests or glute activation tests have been able to tell so much about swimming performance as POS exercise. There are optional tests for core activation that are usable. 

Sorry to say, that the public video of POS exercise is still not ready. The development programs have kept me busy. I see a need for POS part III, as I think we should address the kick and its role in the bigger picture. Would you agree?  



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6 Comments on "Posterior Oblique Sling Enhancing Swimming Performance, Part II"

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I am not sure if it is me, or if it is because i missed Part II but I don’t get it and wish it were explained in every day English.

Jukka Shemeikka

Hi Crawler

You can find the first part here:

Any questions you come up with, I will be happy to answer!

Jukka Shemeikka
Head of Aquatics
Olympic Training Center Rovaniemi

Jukka Shemeikka, definitely interesting information, I would be interested in learning and possibly sharing some data / info I have as well. We use muscle fascia training within our dryland and also introduce it’s concepts in water as well, although that is much harder to do based on the aquatic environment, could you send an email to [email protected] Thank you

Jukka Shemeikka

Hi Tim

Just sended you an email. Hope you got it.

As swimmers, we like biomechanics to be as concrete as possible. So when you say – initiate the arm stroke by kicking up with opposite side leg when the arm reaches catch position – this is something that we can understand (I believe that when you say “the arm stroke”, you are referring to the pull phase).

So now I am going to slightly alter your sentence to help better understand your instructions:
After the arm reaches the catch position, initiate the pull phase by kicking up with the opposite side leg.

My initial reaction to this is that is the timing between the arms and legs in freestyle something I need to think about? Isn’t this timing instinctual after years of swimming?

Jukka Shemeikka
Hi Aftershock Thanks for that! That sentence makes more sence now 🙂 Yes, we should think about the timing. I think it is more of a common misunderstanding, that everything just falls at it’s place by swimming a lot of reps. I’m not saying, that it isn’t possible, because it can be, but it is rarely achieved. With years of training we do find the best movement that suits our qualities, and it can look effortless. It still might not be the best possible choice. I could show this better, than put it on writing (clearly :)). When we analyze a swim, there’s a clear pattern to be found in every performance. Some of those performances are more efficient than… Read more »