Interactive Forum: Extension

[EricMatuszewski]

Does anyone have a recommendation as to what the elbow joint should do?

Should there be no conscious attempt to flex or extend it?

Or should flexion or extension contractions take place?



Also does anyone have any ideas about how the arm should flex?

I think it's common for people to think of arm flexion as extension, (yes symantics again) so there's confusion there as well.

Specifically what is the advantage of the arm flexing to closer to 90deg in relation to the torso (when viewed from the side) or possibly greater (as in a reverse followthru).

Is there an advantage to not flexing the arm as much in some situations?

There's alot to talk about here.

[BrianGordon]

Does anyone have a recommendation as to what the elbow joint should do?

Should there be no conscious attempt to flex or extend it?

Or should flexion or extension contractions take place?



Also does anyone have any ideas about how the arm should flex?

I think it's common for people to think of arm flexion as extension, (yes symantics again) so there's confusion there as well.

Specifically what is the advantage of the arm flexing to closer to 90deg in relation to the torso (when viewed from the side) or possibly greater (as in a reverse followthru).

Is there an advantage to not flexing the arm as much in some situations?

There's alot to talk about here.

One more for the road-

The elbow should remain fixed in whatever orientation is deemed best by the coach and player, based on understanding of the mechanics that the elbow angle dictates, which is where we were headed early this morning.

Therefore, there should be no conscious effort to flex or extend.

And yes there will be both flexion and equal extension contraction to maintain this static(isometric) condition.

It is hard to answer the 4th question because arms don't flex or extend, joints do. So if you are referring to the elbow, it should not flex or extend. The shoulder does flex in the first half of the forward swing, then flexes and/or horizontally adducts late depending to a great extent on the elbow angle one chooses - one of the mechanical repercussions of that choice.

Flexion is bending the elbow, extension is straightening it.

The last two questions don't make much sense - but assuming you now mean the shoulder joint then you are referring to the shoulder abduction angle which has a huge impact on several mechanical factors - is related to choice of elbow angle combined with technique - and is finally starting to address gsheiners line of reasoning from earlier.

And finally, Eric, you were much more entertaining answering questions than asking them and I mean that in a good way. Keep up the good work and good luck - Brian

[jeffreycounts]

Interesting discussion folks (and nice visuals). It is a topic we've researched extensively at our 3-D center in Cincinnati. In the process I have defined most of the pros and cons of a "double bend" vs. "straight arm" approach from a mechanical perspective. Many have danced around the periphery of a few of our findings. I would suggest however that the post by gsheiner (especially point #1) provides a template for thinking that will produce the answers you seek. While the specifics of his post are not completely accurate (he does pose them as a question), his implicit direction in considering the way each technique alters the dynamic interactions among the body segments and racquet will yield the answers to the benefits and detriments of each. Have fun - Brian

In terms of gsheiner's point number one explaining the straight arm forehand, I just don't see it with Srichaphan's forehand. Maybe I am missing something, but I don't see how his "elbow is viciously bent during the swing". I don't think a rapid fire elbow movement explains his straight arm forehand at all.

[veena]

The differences that I see between Srich. and Fed with the straight arm is that while Srich. keeps his arm straight through the entire swing, while Fed bends his hitting arm almost after the ball his hit, unless if he is hitting a higher ball/hitting a ball more aggressively. Just my $.02

Roger: Nadal: http://www.tennisplayer.net/members/...ideInSide6.mov

Srich: http://www.tennisplayer.net/members/...sideInSide.mov

[jeffreycounts]

The differences that I see between Srich. and Fed with the straight arm is that while Srich. keeps his arm straight through the entire swing, while Fed bends his hitting arm almost after the ball his hit, unless if he is hitting a higher ball/hitting a ball more aggressively. Just my $.02

Roger: Nadal: http://www.tennisplayer.net/members/...ideInSide6.mov

Srich: http://www.tennisplayer.net/members/...sideInSide.mov

I agree with you completely about Srich. and Fed. But it seems to me that Nadal's arm remains straight for a pretty long time after contact.It seems to me Nadal turns his hand to get a lot of torque on the ball, but doesn't use his elbow like Federer.

This has been a very interesting discussion for me. I didn't realize how Federer's use of the elbow bend (bicep muscle?) was unique to his forehand. He seem to use his hand and bicep to create torque on the ball right after the straight arm contact.

This discussion has even furthered my conviction that the Federer forehand is not a great model to copy. It is so unique to him and so sophisticated technically, that I question two popular coaches (who shall remain unnamed) that try to teach the Fed forehand to everyone and claim it is the future of tennis. Like I said in a previous post, we may never see this kind of technical complexity again. And certainly not a player that can mix up his forehands like Fed does, from almost a double bend forehand at times to his trademark straight arm sling shot rockets.

[EricMatuszewski]

The shoulder does flex in the first half of the forward swing, then flexes and/or horizontally adducts late depending to a great extent on the elbow angle one chooses - one of the mechanical repercussions of that choice.

- Brian

This answers my question regarding "flexing the arm" sorry for the sloppy word choice, that's what happens when I try to avoid saying gleno-humeral joint.

and thanks for the compliment, I'll answer more questions for entertainment sake when the posts counts get closer to the views counts on these things. I'd like to see more participation on this board the disparity between views and posts is astounding.

[EricMatuszewski]

The 90deg "shoulder" flexion question is in regards more to what Jeff brought up in the Youznhy post. See the red right angle showing the degree of shoulder flexion.

My question is, is it an advantage to flex the shoulder to this extent all the time? Is less flexion ever called for? The "reverse" finish seems to be an example of taking this another level.

What effects do each of these levels of maximum shoulder flexion produce.

I've heard some say it increases ball depth, others say it causes increased topspin. What do you all think?

[jeffreycounts]

The 90deg "shoulder" flexion question is in regards more to what Jeff brought up in the Youznhy post. See the red right angle showing the degree of shoulder flexion.

See attached pics...

[lukman41985]

My opinion is that the more the elbow flexes through contact, the less the shoulder flexes.

For me, using elbow flexion on the forehand is very difficult to time. I get much more control and consistency when I let the shoulder power the stroke. I also seem to get more depth. Though, I can sure wallop some drop feeds with a forehand powered by a maximum use of elbow flexion. How that translates to actual rallying...not so good.

With regard to Nadal and Federer, it's not either/or. They sometimes flex the elbow and sometimes they don't; correspondingly, they sometimes flex the shoulder and sometimes they don't. These guys have way too much variety too make an end all judgement. Check out the following clips.

Federer--less elbow flexion, more shoulder flexion:

Federer--more elbow flexion, less shoulder flexion:

Nadal--less elbow flexion, more shoulder flexion:

Nadal--more elbow flexion, less shoulder flexion:

[lukman41985]

How about a hand for Jeff's visuals?

Jeff,
How the heck do you produce such great visuals? What kind of programs are you using to freeze frames, draw lines, etc. You make your points so damn clear, it's ridiculous.

[jeffreycounts]

My opinion is that the more the elbow flexes through contact, the less the shoulder extends.

For me, using elbow flexion on the forehand is very difficult to time. I get much more control and consistency when I let the shoulder power the stroke. I also seem to get more depth. I can sure wallop some drop feeds though with a forehand powered by a maximum use of elbow flexion. How that translates to actual rallying...not so good.

With regard to Nadal and Federer, it's not either/or. They sometimes flex the elbow and sometimes they don't; correspondingly, they sometimes do extend the shoulder and sometimes they don't. These guys have way too much variety too make an end all judgement. Check out the following clips.

Federer--less elbow flexion, more shoulder extension:

Federer--more elbow flexion, less shoulder extension:

Nadal--less elbow flexion, more shoulder extension:

Nadal--more elbow flexion, less shoulder extension:

Excellent job!!

I think you have captured an essential componenet of these forehands. The shoulder helps drive through for more extension on some shots and the elbow flexion across the body shortens the extension but increases the torque on the ball.

[jeffreycounts]

Jeff,
How the heck do you produce such great visuals? What kind of programs are you using to freeze frames, draw lines, etc. You make your points so damn clear, it's ridiculous.

Thanks! I use the most basic tools imaginable. Just Flash and Photoshop.

This forum is awesome with the ability to upload images and videos. I didn't realize how amazing this technology was.

[lukman41985]

Jeff,
Quick question: did you use Dartfish to generate those "rainbow" images of Mariano Z. and Nalbandian? Also, how are you able to isolate an image from a single frames of video as you did with the Hewitt and Youzhny images?

[lukman41985]

Perhaps this will show what I'm talking about more clearly

Roger...
Less shoulder flexion, more elbow flexion:

More shoulder flexion, less elbow flexion:

[lukman41985]

Food for thought...

1.)So now I'm facing this question, and it's a question John asked in the first post of this thread: how do we "measure" extension? Is the shoulder our main reference point in this determination? I believe this to be the case. How about you guys?

2.)What is the relationship between shoulder flexion and shoulder rotation? It seems to me that the more shoulder flexion one has, the more the shoulders rotate.

3.)Out of curiosity, can anyone locate a clip that shows a player hitting with a lot of shoulder flexion and a lot of elbow flexion? I'm going to look as well.

4.)Let's consider James Blake. Check out his forehand clips in the stroke archive. Notice that all of his forehands are hit with lots of shoulder flexion and never with any observable elbow flexion. This, in my mind, limits his variety off of the forehand side. Notice I said it limits his variety. James generates mind-blowing velocity and a relatively flat ball. Be mindful of the fact that a flat ball, which produces a lower bounce, is not all that tough to handle for someone standing up on the baseline--say someone like a Roger Federer. However, the lower bounce would trouble someone standing far back--say someone like a Rafael Nadal. The Blake-Nadal matches are a treat to watch because you can see James working Rafa up and back, and once Rafa's falls back far enough, James will hit powerful angles off both wings from wide positions. Rafa nearly has the variety Roger does off of the forehand wing, but his court positioning is detrimental for his matchups against Blake. Roger, standing up on the baseline, is basically unfazed by the lower bounce off the Blake forehand. Anyone else notice these things?