#rowing video

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Rowing Stroke Video Analysis

Rowing Video Analysis

The following is a guest post by Johannes Rudolph from rowinginmotion.com. He was a sucessfull junior rower and is currently a youth team coach at a german rowing club. His email is  [email protected]. Video analysis has been very popular in the Rowing Community since the days when consumer-grade video recording equipment became available. Technology has changed drastically now that every modern Smartphone is equipped with an HD camera, which opens exciting opportunities for coaches and athletes. Recording and reviewing video material has become so much more convenient, that we see rowing coaches recording footage in almost every training session. This gives athletes the best feedback possible right after each session and enables them to work on improving their technique more effectively. Rowing has several unique challenges when it comes to recording video analysis that is meant to serve as the basis for future comparison. Contrary to golfing, we don’t enjoy the benefits of a fixed camera position when following behind with a motorboat. Oh, and since rowing is not a sunny Sunday sport, you have to cope with the occasional rain too, so make sure to bring a waterproof case! Tools like Ubersense can help us compare rowing technique and visualize important aspects. My recommendation is not to focus on absolute angles or other measures that you can apply with Ubersense, but instead try to visualize certain aspects of the motion sequence you’re dissecting. The video material I will present in this post is not a “normal” sports video. Instead, these are “Rowing in Motion Videos” recorded using the “Rowing in Motion” Apps. Rowing in Motion is a highly innovative measurement system for rowers and coaches that uses an iPhone in the rowing boat to measure speed, stroke rate and most importantly boat acceleration. This image should give you an impression how the iPhone is mounted into the boat (it's in the white waterproof case at the left)

The boat is decelerating heavily right before the catch. This is caused by the athlete pushing on the stretcher, to slow down his body mass moving towards the stern. We see a nice forward position with stretched arms, lower legs vertical and blades about to hit the water.

In the next frame we see two important things. The boat has stopped decelerating (red circle) and should start accelerating any moment. The angle between upper body and the boat has already opened significantly. This is suboptimal as we will see in the next picture.

Looking at the acceleration graph, we see that the boat starts to pick up speed just now. What has happened in between? Nothing really, at least nothing that accelerates the boat. This is a result of the too early lifting of the upper body between the first and second picture, which makes it hard for the athlete to exercise a proper leg-push. (And the legs are much stronger than the upper body).

To round this up, we take a look at the end of the leg drive. This is close to the point where we see the maximum boat acceleration. This is due to several bio-mechanical factors, most notably that the angles between rower and oarlock are optimal (90°) and the leg muscles can exercise their maximum force.

Second Stroke

In the next stroke we want to take a look at it, the same athlete does a much better job keeping is upper body in a forward position during the drive, thereby achieving a higher boat acceleration in the critical phase after the catch.

  As we can see here, the catch is performed by lifting the arms. That's the way it should be, instead of lifting the whole upper body. Note that we're measuring the angle of the upper body relative to the legs this time, to better visualize this.

Let's round up what happens in the next phase of the drive. The upper body starts lifting slightly now, and the boat acceleration reaches a very short plateau before it will take a steep rise to the maximum. When comparing the shapes of the acceleration graphs between the first stroke we examined and this one, we clearly see the improvement in the first part of the drive phase

Wrapping up

We have seen how useful using Ubersense is with Rowing Videos to visualize and compare certain aspects of the rowing stroke. Not having a fixed camera makes some of the advanced features like the excellent video comparison less useful. (It works very well with indoor rowers though!). One of the best features in the new 2.0 version of Ubersense is the ability to tag the videos by different crews, so you can easily track their progress over the season. Have your recorded your rowing stroke? Leave a comment below to let us know what you learned.