Posted tagged ‘vaulting’

Some Compulsory Vault Drills I use

January 3, 2015

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The Hurdle – Part II

January 27, 2010

In the first blog post on the hurdle, I discussed the importance of the position of the back leg at initial contact after landing during the brief flight phase of the hurdle.  Furthermore, as shown in the videos, the back leg seemingly pulls in under the gymnast or even slightly in front of the gymnast’s hip(s).

Even with a background in biomechanics, I could not figure out a mechanical reasoning for this phenomenon.  Why do many of the best tumblers do this?  How does it give them an advantage?  After much thought, I think it’s no different than why landing the feet in front of the body for forward vaulting is necessary. In vaulting, as the feet contact the board and are essentially “stopped,” the rest of the body continues to travel forward due to its horizontal momentum. How far the feet should be in front obviously depends on the speed (velocity) of the athlete. Athletes who are very fast will need their feet further in front, because they tend to generate much greater momentum. If the feet are not far enough in front, they are too far forward, too much rotation is created, and the athlete struggles to get enough of an upward flight trajectory to effectively contact and/or clear the vaulting table.

In the floor hurdle, I believe that the initial foot (leg) must contact directly underneath or even slightly in front of the hip to allow a more optimal position of the center of mass. Whether its underneath or slightly in front will again be dependent upon the velocity and the momentum generated by a particular athlete. If the athlete does not pull the initial leg under upon contact, they must compensate in some way so that they remain “stable” as they are transitioning into the round-off.  (At :52 into the Cheng Fei video, if you stop the video, you will see what I am talking about.)

So, how does the gymnast compensate if they do not pull the leg in under them? From my observation, they often push the hips backwards, which is completely opposite of what you want to happen!  This allows a better position of the center of mass so that they remain stable and do not lose their balance. Another compensation is kicking the leg around the side in some fashion. (There are other issues that cause this, of course…head position, etc. so if your athlete kicks their leg around the side of a round-off, don’t assume it’s purely a hurdle issue. I am just citing another possible compensatory strategy)

(Also, as a side note, if you watch kids who do not bend the front leg knee in the lunge as they land out of the hurdle, their hips move backwards as well. That’s why lunging is so important! Teach your kids to lunge when they first walk in the gym!)  Look back at Troy’s post on handstands!

Another thing to consider when we’re talking about the hurdle is the position of the body. The body should be upright with no closure at the hips. Many gymnasts “reach” to the floor and do so by bending (piking) at the hips. The body should act like a lever and pivot over the lead (“lunge”) leg with the back leg initiating the “kick” over the top. The gymnasts should think about “kicking” the back leg to turnover – not reaching to the floor. The weight of the head, arms, and trunk (HAT) actually helps to create an additional torque (rotation) as the body is pivoting over that lead leg and should be helpful to the overall turnover in my opinion in addition to the active “kicking” of the back leg.

However, if the upper body bends down at the waist too soon, the gymnast has lost this additional torque and may also create stability problems because their center of mass will now move too far forward of the lead leg over which they are pivoting. I believe that this, too, can cause a gymnast to innately move the hips backwards as well as to kick around the side.

So, I promote a hurdle that moves up and forward and stress getting the initial contact leg in underneath or even slightly in front of the contact leg’s hip. I also promote an upright body position and any leaning is a total body lean that is caused by the bending of the lead knee (i.e. passing through a lunge) just prior to the back leg “kick” and the body pivoting over the lead leg. Another thing about the lunge is that when the knee is extended (push-off from the lunge), that also contributes to the angular momentum that is being created.

Hopefully, all of that makes some sense and gives you something to think about.

Lastly, the hurdle is like any other skill. Spend some time teaching it. Don’t assume that gymnasts know how to hurdle.

Here is another excerpt from the same lecture given by Stacy Maloney, who used to coach Paul and Morgan Hamm, if  you are not familiar with him.

This shows how he trains his athletes to get their back leg in underneath them so that it is in a position to aid in rotation.

Again, I apologize for the poor sound quality.  I dubbed this video from someone else – from VHS to VHS and I used Dazzle software to convert it to digital format.  If you use headphones or turn up your speakers, you should be able to hear it.

Finally, here is another drill that I found recently  HERE , which was posted by Coach Bart who runs the blog and also hosts the site Gymnastics-Skills.com

The Hurdle – Part I

January 26, 2010

I wish that I had some pictures to express what I am about to discuss, but I do not unfortunately.  To follow along, the best that I can do is have you reference a YouTube video of Cheng Fei’s Yurchenko 2 1/2 from 2005 World’s in Melbourne.  At :51 seconds in, there is a side view in slower motion.  If you stop the YouTube player, you can see much of what I describe below.  I tried to create screen shots, but the camera quality is not good enough and it’s too blurry.

The hurdle by definition is simply a transition from a run such that the athlete can maintain as much of the horizontal momentum as possible that was generated from the run into their tumbling skill(s) or vault.

When walking/running, the center of mass is constantly moving upwards and downwards. With that said, the goal is to keep the center of mass as constant as possible as any major displacement will affect the horizontal momentum that has been generated.

Despite this, I believe that there should be a bit of a vertical component to the hurdle. I like to see the hurdle go both upwards and forwards. Will you lose a little horizontal momentum? Yes. The same happens in vaulting. But, I believe it’s minimal. The reason that I feel that you must go slightly upwards is because of the back leg and where it contacts the ground.

David Kenwright, Olympic coach in Canada, and someone that I respect greatly, teaches his athletes to try and “scoot” or “shuffle” (I believe is his terminology) their initial contact leg (which is the “kicking” leg of a round-off/cartwheel) underneath of them as it initially contacts the ground. When watching the top tumblers, this definitely seems to be a trend as all of the best do it. Whether they were taught or they do it naturally, it happens.

Stacy Maloney, head coach/director at Swiss Turners in Wisconsin, is another person that I heard discussing the importance of the position of the back leg.  I have uploaded an excerpt from a lecture that he gave at the 2003 Region IV Congress (I believe…I dubbed this from another coach) where he discusses three important aspects of the RO.

Note:  I apologize for the poor sound quality.  I dubbed this video from someone else – from VHS to VHS and I used Dazzle software to convert it to digital format.  If you use headphones or turn up your speakers, you should be able to hear it.

In part II, I will look a little more at the mechanics of the hurdle and my mechanical rationale for the importance of the position of the back leg as such.