Forehand & Serve Video Analysis

[Bendex]

What do you guys think of my analysis?
Forehand: https://www.youtube.com/watch?v=wI6nD2NHGZA
Serve: https://www.youtube.com/watch?v=uGe120Z-ljQ


So I inherited some students from another coach who left town. The kids are all quite good players for their age, but have some very 'unique' techniques. She was very strict and the kids did a lot of running, and hit a lot of balls. But she wasn't very concerned with their technique. She had most of the best u10 players in town, so I can't fault her approach too much. (The kids also dominate long distance events at school )

I've been trying to gradually correct each of them through video and extra sessions with a few at a time. Have any other coaches here faced a similar situation with a mass number of experienced juniors with strange in-ground technique?

There was some push back at the start when I tried to correct them too vigorously, without any success. For now I'm resigned to it being a very gradual process.

 

[julian]

See Figure 5 of the document

What do you guys think of my analysis?
Forehand: https://www.youtube.com/watch?v=wI6nD2NHGZA
Serve: https://www.youtube.com/watch?v=uGe120Z-ljQ


So I inherited some students from another coach who left town. The kids are all quite good players for their age, but have some very 'unique' techniques. She was very strict and the kids did a lot of running, and hit a lot of balls. But she wasn't very concerned with their technique. She had most of the best u10 players in town, so I can't fault her approach too much. (The kids also dominate long distance events at school )

I've been trying to gradually correct each of them through video and extra sessions with a few at a time. Have any other coaches here faced a similar situation with a mass number of experienced juniors with strange in-ground technique?

There was some push back at the start when I tried to correct them too vigorously, without any success. For now I'm resigned to it being a very gradual process.

In reference to your serve video
Please see Figure 5
https://secure.ausport.gov.au/__data..._in_Tennis.pdf

If you have some problems with an access please do as follows:
google "elliot serve secure"
google will produce a list of documents
click a document described above
It should allow you to access it

Julian W.Mielniczuk
USPTA pro
PS I would suggest to draw a trajectory of a head of a racket in the case of the boy in a blue shirt and compare with a corresponding trajectory of Djokovic.
The boy is in the trophy position TWICE-please see the slow motion part

 

[LeeD]

This is ridiculous!
Kid is a beginner, hasn't developed anything in his game, and you're comparing his strokes with Novak's?
Posting any vids of pro players NOW, at this kid's level, is pure stupid thinking on YOUR part.
Learn the basics, then adapt and evolve LATER.

 

[RajS]

Oh my my! I feel like I saw my doppelganger from the future in that kid with the straight and low takeback! Although I am far from an expert on these matters, I think I understand why it happens. Notice the really low ball bounce. I have a feeling that a big loop doesn't help with such balls. If someone habitually plays on courts where the ball comes fast and low after the bounce like I have, he or she is likely to develop a straight and low takeback, again like me I think. But since I have recently been playing on a court where the bounce is much higher, I have found myself using a higher backswing - but not too high, just high enough, since I've found it's futile to fight my muscle memory at this stage. Is there any fundamental problem with this approach, other than maybe some power is sacrificed?

 

[GuyClinch]

I don't know why people are hating on your video OP - pretty good in my estimation. I didn't watch the serve one yet..but nothing wrong with the forehand one.

My only issue is that the transition from full L backswing from 'low and straight' backswing is actually fairly tough..

 

[WildVolley]

I thought the video was good in that it identifies the need for getting the elbow into the proper position for a good serve.

Now, the trick is what drills will get the student to learn and feel the proper position while learning the serve.

 

[Bendex]

This is ridiculous!
Kid is a beginner, hasn't developed anything in his game, and you're comparing his strokes with Novak's?
Posting any vids of pro players NOW, at this kid's level, is pure stupid thinking on YOUR part.
Learn the basics, then adapt and evolve LATER.

It IS later.

Maybe I should have elaborated more that these are experienced players who have been training with the other coach since they were little. They both made a final this weekend in their age groups.

The kid with the strange serve actually gets it in about 90% of the time, it just doesn't have much pace.

 

[Topspin Shot]

This is ridiculous!
Kid is a beginner, hasn't developed anything in his game, and you're comparing his strokes with Novak's?
Posting any vids of pro players NOW, at this kid's level, is pure stupid thinking on YOUR part.
Learn the basics, then adapt and evolve LATER.

There's nothing wrong with using a pro as a model at any level.

 

[Bendex]

Oh my my! I feel like I saw my doppelganger from the future in that kid with the straight and low takeback! Although I am far from an expert on these matters, I think I understand why it happens. Notice the really low ball bounce. I have a feeling that a big loop doesn't help with such balls. If someone habitually plays on courts where the ball comes fast and low after the bounce like I have, he or she is likely to develop a straight and low takeback, again like me I think. But since I have recently been playing on a court where the bounce is much higher, I have found myself using a higher backswing - but not too high, just high enough, since I've found it's futile to fight my muscle memory at this stage. Is there any fundamental problem with this approach, other than maybe some power is sacrificed?

Yes, these courts are low bounce, but he has only been training here for 6 months. He grew up on hard courts (and always struggled against his peers). I'm using Micro X balls which bounce quite high, and I feed bouncy balls most of the time. He has actually improved a lot lately. I'm sure our low bouncing courts are giving him longer rallies and more confidence. We talk often about why he struggles so much on bouncy courts, and he wants to adjust.

The major problem with his straight back technique is that when he gets nervous he finds it very difficult to swing fast. In tournaments he sometimes ends up playing half court tennis against kids he would easily over power if he was swinging freely. I think a longer swing will help him maintain depth, even when his arm refuses to accelerate.

 

[LeeD]

Teach basic straight back then forward swings first, allow the kid to embellish as he sees fit, but don't teach him the ErnestGulbis forehand EVER. Allow him to hit that style if he wants and if the can hit it well.
Teach basic StanSmith service motion, allow the kid to embellish with McEnroe's motion, or Roddicks, but don't TEACH HIM that motion, there's too many parts.
Teach basic McEnroe topspin backhand. ALLOW him to embellish and use Gasquet's or Warwrinka's backhand.

 

[Bendex]

Teach basic straight back then forward swings first, allow the kid to embellish as he sees fit, but don't teach him the ErnestGulbis forehand EVER. Allow him to hit that style if he wants and if the can hit it well.
Teach basic StanSmith service motion, allow the kid to embellish with McEnroe's motion, or Roddicks, but don't TEACH HIM that motion, there's too many parts.
Teach basic McEnroe topspin backhand. ALLOW him to embellish and use Gasquet's or Warwrinka's backhand.

After my experience with these strange techniqued kids, I think it's better to just teach them properly in the first place. It's so hard to change them once they've hit millions of balls. With my beginners, I spend some time every lesson going over the optimal swing paths and elbow positions.

Here is the swing path drawing that someone asked for: http://youtu.be/Wh8GpqjqU1o

 

[LeeD]

One major problem with your teaching is that you seem to teach the entire swing, from prep position to followthru.
You should get the kids started at TROPHY position first, then hit the ball from there. Allow them to find their path from prep to trophy. What counts in a serve is from trophy position onward, and you know that kid's elbow is too high, there is no tilt in the shoulder, there is no archer's bow. Lower the kid's elbow, tilt his shoulders toss arm up, racket arm shoulder LOWER, and push his hips forward.

 

[Chas Tennis]

Camera Viewing Angles for Comparisons

I have been looking mostly at serves and developing some checkpoints based on pro or other high level serves.

The camera viewing angle is important for comparisons. The player is serving from the doubles alley. It looks as if in your comparison, the camera is viewing along the baseline for the young player but the camera is viewing from a much different angle for Djokovic, perpendicular to the baseline. ?

For the serve, I selected two camera viewing angles: 1) along the ball's trajectory, usually from behind, and, 2) perpendicular to the ball's trajectory. I've developed some experience with some serve checkpoint angles from these two camera perspectives. Other viewpoints are also options but I'd limited them to gain experience. Along the center line - very often used - is not optimal for either ad or deuce serves.

The racket tracks that you displayed especially will not compare from different camera view points.

I've analyzed poster's serves using a few checkpoints from these two camera views. I adjust as best I can for the camera angles that were used by posters. It is much easier for me to see some important angles if the posters take a camera view looking approximately along the trajectory from behind. Otherwise, I'm trying to figure the effect of the camera viewing angle.

Angles at impact seen well from behind viewing along the trajectory:
1) whether the arm appears straight (as viewed from behind)
2) the forearm-racket angle (as viewed from behind)
3) an angle for the shoulders and hitting arm to compare to the recommendations given in the Ellenbecker video and high level serves. High level servers I estimate typically have their upper arm up somewhat, 10-20 d. ? from the line draw between the two shoulders.
4) overall body angles, toss location......
5) others

From the side camera view other angles can be compared along with forward body motions:
1) racket angle at impact, opened or closed (this is a separate component of the racket angle as that seen from behind)
2) arm forward angle at impact (this is a separate component of the arm angle as that seen from behind)
3) body angle at impact
4) head position relative to the ball, were they looking? In my opinion based on high speed videos, most pros probably aren't still looking at impact.
5) others

Generally, with a camera looking along the ground and with one side of the frame vertical you can get accurate information on the height of objects from all camera view points around the court - you can most often compare heights reasonably well as you have done. However, with some camera angles, the other two dimensions can fool you. For example, from the side you see the racket height well but don't notice that for a high level serve the racket is tilted toward the camera at a considerable angle. (This has fooled us all for many years on the serve.)

The fastest and most important part of the serve, internal shoulder rotation, lasts only about 25 milliseconds. So a 30 fps video camera, that takes just one frame every 33 millisecond, at best, can catch only one randomly timed frame. You can never see the internal shoulder rotation. High speed video is necessary to see the faster parts of the serve.

For serves analyses, pictures, angles, etc. search TW threads: camera behind Chas Tennis

 

[julian]

Go in a slow motion

It IS later.

Maybe I should have elaborated more that these are experienced players who have been training with the other coach since they were little. They both made a final this weekend in their age groups.

The kid with the strange serve actually gets it in about 90% of the time, it just doesn't have much pace.

Go in a slow motion and see that the boy in a blue shirt lands in a trophy position TWICE.
You have to decide whether you want to change it or not.

 

[Chas Tennis]

Shoulder Angle to Reduce Impingement Risk - The Ellenbecker Video

My interpretation of the upper arm position and shoulder orientation -

At impact it's not perfectly in line or at 90° of abduction for high level servers. It is usually more like say 100 or 110° at impact. See high speed videos. It may well often be close to 90° of abduction in the external shoulder rotation phase of the serve around the trophy position. See videos.

It is also a little more complicated since the scapula moves around on the body........... Scan down to half way through this golf swing article to find a back view of Nadal serving. That is his scapula moving up and rotating. Scapular motion affect impingement risk.
http://www.aroundhawaii.com/lifestyle/health_and_fitness/2011-03-whats-a-shoulder-turn-part-3.html

Pre-stretching of the internal shoulder rotation muscles -
Since you want external shoulder rotation to pre-stretch the ISR muscles you want the upper arm, forearm and racket in a position so that external rotation is caused by the leg thrust and other motions. I guess this external rotation phase is not the greatest impingement risk. But see the Ellenbecker video and don't take my interpretation.

My interpretation of the Ellenbecker video is that when the violent internal shoulder rotation occurs approaching impact that might be the more risky time for impingement.

But study the Ellenbecker video for yourselves.

The young player raises his shoulder very high early in his motion. Is that a problem without the internal shoulder rotation or the external rotation? If the technique is different than the high level serve I don't think that there is another video similar to Ellenbecker's for guidance - no guidance for unique serving techniques. Also, the high level servers don't tend to raise the shoulder early in the motion although some may to some degree. Find videos.

But if you have an internal shoulder rotation serve, not understanding the Ellenbecker recommended shoulder orientation is risky.

 

[Irvin]

Tennis is 90% (or more) getting to the ball. Hitting a winner after a long rally or getting lucky and hitting a winner off one of you opponents great shots is much better than an ace or service return winner. Get to the point where you're worn out after the first set and you're done.

 

[RajS]

@Bendex: Thanks for your response, and wish you all the best with your protégé.

 

[julian]

Swing path is much longer

After my experience with these strange techniqued kids, I think it's better to just teach them properly in the first place. It's so hard to change them once they've hit millions of balls. With my beginners, I spend some time every lesson going over the optimal swing paths and elbow positions.

Here is the swing path drawing that someone asked for: http://youtu.be/Wh8GpqjqU1o

A swing path is much longer.
Please compare with a paper I quoted.
Please see my post number 2 of this thread.

 

[Bendex]

A swing path is much longer.
Please compare with a paper I quoted.
Please see my post number 2 of this thread.

Hi Julian. I wasn't able to track down the file on Google. Do you have a direct link that doesn't require a login?

 

[julian]

Login will not work

Hi Julian. I wasn't able to track down the file on Google. Do you have a direct link that doesn't require a login?

Login will not work
Please read post number 2 and try to "go" via google.
Google did work for me
If google does not work I will try to find another reference
Try to talk to someone how to draw trajectories in Dartfish.
Your first piece is correct but you did not finish it.
I was trying to make a point that the boy has two trophy positions instead of one.
See my post number 14 above

 

[Bendex]

Going to have to disagree with LeeD using pros as an example for kids is perfect. its very visual for them and they enjoy it as they want to emulate their heros.

As for the two shots

Serve: What happens when instead of bringing the tossing arm up so high he starts with it lower, giving it less distance down the way to travel before it starts to come back up to release the ball which may help with the synchronization of the two arms?

Then deal with the high elbow.

I agree, the kids get excited when you compare them on video to the pros. And I don't think there's anything particularly hard about starting and finishing with a high elbow. I have some 7 year old girls doing it after their 3rd lesson. I'm not getting overly technical with them.

Here in Australia, a lot of tournaments are played on those gritty high bouncing blue courts, so all the best 17 year olds you see here these days have developed very high elbow take backs (See Nick Kyrgios for example). I know most of them probably developed it naturally as an adaptation to the high bounce, but it can't hurt to teach the preteens as early as possible.

 

[Bendex]

Login will not work
Please read post number 2 and try to "go" via google.
Google did work for me
If google does not work I will try to find another reference
Try to talk to someone how to draw trajectories in Dartfish.
Your first piece is correct but you did not finish it.
I was trying to make a point that the boy has two trophy positions instead of one.
See my post number 14 above

Yes, it sort of is two trophy positions. People beg me not to change it because it's his trade mark... an endless source of amusement, and none of the other kids can replicate it.

I found a pdf on that site, but it was called "Stroke production in tennis." Is that correct?

 

[julian]

It is the correct paper

Yes, it sort of is two trophy positions. People beg me not to change it because it's his trade mark... an endless source of amusement, and none of the other kids can replicate it.

I found a pdf on that site, but it was called "Stroke production in tennis." Is that correct?

It is the correct paper.
Could you see Figure 5?
Could you provide a trajectory in your case and compare with Figure 5?
Some trajectories are produced in a different thread at THIS forum.
Please go to the section Rackets in the section Tennis Equipment
Please find some post with pictures in the Sticky:
Tennis Warehouse Zepp Tennis Sensor Playtest

Switching gears:
Do you have any coaching materials from Tennis Australia about serve?
Do you know why your trajectory produces "less" power ?
A partial answer is that
The boy basically doubles the kinetic chain.
Switching gears:
Why serve should be an endless source of amusement?

 

[Chas Tennis]

This worked to show me the paper.
https://secure.ausport.gov.au/__dat...380883/No._27_Stroke_Production_in_Tennis.pdf

That 1990 paper is significantly outdated for the serve mostly by Bruce Elliott's own work. Elliott published a paper in 1995, if not before, that indicated that internal shoulder rotation was the most significant contributor to racket head speed at impact.

I believe that the 1995 paper and many others are listed here. See Elliott references.
http://tt.tennis-warehouse.com/showthread.php?t=427364

Bendex, have you taken any of the coaches training from Elliott and others?

Elliott's book Technique Development for Tennis Stroke Production, 2009, B.Elliott, M. Reid, M. Crespo is an excellent reference on the strokes. It also includes some developmental information on what children might do at given ages. (However, I don't like the one hand backhand chapter as much as the other chapters and my copy has typos. ??)
Also, the Biomechanics of Advanced Tennis (2003), B. Elliott et al.

 

[Chas Tennis]

Very nice video analysis of the early phase of that serve.

I always like to see more connection and discussion of the basic stretch shortening cycle that drives the serve.

External shoulder rotation pre-stretches the internal shoulder rotator muscles. Release of the pre-stretched internal shoulder rotators accelerates the racket to strike the ball.

Reference Biomechanics of Advanced Tennis (2003)

Video Limitations. High speed video is necessary to see the service motion. All instructional videos on serving technique should be done with high speed video. Otherwise, what is shown and your comments are limited to the slower parts of the motion such as the take-back and start of the forward swing. The most important phase of racket acceleration and ball impact will always be shown as only one random frame.

 

[Bendex]

Very nice video analysis of the early phase of that serve.

I always like to see more connection and discussion of the basic stretch shortening cycle that drives the serve.

External shoulder rotation pre-stretches the internal shoulder rotator muscles. Release of the pre-stretched internal shoulder rotators accelerates the racket to strike the ball.

Reference Biomechanics of Advanced Tennis (2003)

Video Limitations. High speed video is necessary to see the service motion. All instructional videos on serving technique should be done with high speed video. Otherwise, what is shown and your comments are limited to the slower parts of the motion such as the take-back and start of the forward swing. The most important phase of racket acceleration and ball impact will always be shown as only one random frame.

Clearly I need to do more reading on bio-mechanics, since I don't understand some of those concepts. Though I have a big serve myself, so I must be doing something right.

I'm accustomed to keeping things simple for my clientele. At the start I want them to lean over the line, bounce the ball a few times and rest the ball on their strings... I want them to have their elbow some distance from their body at the trophy, and I want the racket pointing to the sky before they start their acceleration. At contact I want them hitting the ball on a slight angle to get some spin (control). I incorporate throwing games into the lessons to develop their throwing mechanics (it's amazing how many 12 year olds can't throw properly these days). Schools don't let the kids throw things in case someone gets hurt. :-?

 

[Chas Tennis]

You have probably seen this video

I believe that serving with ISR is never forced and could cause injury if practiced incorrectly. Here are some known issues. With forceful and rapid ISR the small external shoulder rotator cuff muscles have to be conditioned to keep the ball of the humerus in place and to stop the arm rotation in the follow through. See recommended shoulder conditioning exercises. Easy, light exercises.

There are also the important safety issues related to technique such as the shoulder high orientation for the serve to minimize impingement risk. Just one very bad motion can cause injury.

1) Jim McLennan short video on the rotator cuff, impingement and serving
http://www.youtube.com/watch?v=lTRvxaBMh8s

2) Todd Ellenbecker video on shoulder anatomy, impingement, and serving. At about minute 8 he describes the same issue as McLennan but in more detail.
http://www.tennisresources.com/index.cfm?area=video_detail&vidid=3712&ATT=&reso=lo

If you are concerned because you are having pain, how can you determine that the technique that you use is OK? You have to study and know the proper technique and verify that you are doing it with high speed video or find a well qualified instructor. Keep in mind that the more rapid motions during the serve cannot be seen by eye or even 60 fps video so an instructor who uses HSV is a plus.

It deals with the issue of the orientation of the upper arm during the serve and especially during internal shoulder rotation. To get a good look at this shoulder orientation issue I like the camera view behind the server and along the trajectory.

I am not a coach or instructor. I don't understand the details of how shoulder injuries occur. What Ellenbecker has to say seems reasonable to me and I believe it. I can see in high speed videos that pro servers are orientating their shoulders as he describes. If other serving techniques are used, other than the internal shoulder rotation serve used by the pros today, I don't know what to say.

Google: tennis serve impact pictures
Look at the shoulder orientations.

Google Images is good for searching images. Google Scholar is good for searching references.

I'd like to understand the relationship between throwing and serving along with the differences.
Here is a thread with some information.
http://asmiforum.proboards.com/thread/2104/shoulder-orientation-overhead-baseball-tennis

This is a very basic short review paper - Biomechancs and Tennis by B. Elliott
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/

Tennisplayer.net and other web sites have very detailed analyses of high level strokes.

 

[Bendex]

You have probably seen this video


It deals with the issue of the orientation of the upper arm during the serve and especially during internal shoulder rotation. To get a good look at this shoulder orientation issue I like the camera view behind the server and along the trajectory.

I am not a coach or instructor. I don't understand the details of how shoulder injuries occur. What Ellenbecker has to say seems reasonable to me and I believe it. I can see in high speed videos that pro servers are orientating their shoulders as he describes. If other serving techniques are used, other than the internal shoulder rotation serve used by the pros today, I don't know what to say.

Google: tennis serve impact pictures
Look at the shoulder orientations.

Google Images is good for searching images. Google Scholar is good for searching references.

I'd like to understand the relationship between throwing and serving along with the differences.
Here is a thread with some information.
http://asmiforum.proboards.com/thread/2104/shoulder-orientation-overhead-baseball-tennis

This is a very basic short review paper - Biomechancs and Tennis by B. Elliott
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/

Tennisplayer.net and other web sites have very detailed analyses of high level strokes.

The similarity between a throw and a serve comes down to what I call the "sling shot effect", although "catapult" is probably more accurate. You can't really "teach" this, the arm needs to be conditioned for it.

 

[user92626]

Is the serve like this?

 

[Topspin Shot]

^^^In some ways yes. But the timing of the leg drive is different.

 

[Bendex]

Is the serve like this?

It's a similar throwing motion for sure.

 

[5263]

The major problem with his straight back technique is that when he gets nervous he finds it very difficult to swing fast.

I don't agree and don't see the straight back method as a flaw. Imo it is an option and good to have in the bag for certain situations. Imo the too big tk backs are more of a problem to use and correct...especially for serve rtns. I'd recommend he learn to just modify this tk back a bit to round out the back edge a bit when he has time, but allow the straight back in time crunch situations. you find the loop growing a bit when he has more time and comfort playing. I don't think what he is doing actually contains the negative issues you lump in with it.

 

[Bendex]

I don't agree and don't see the straight back method as a flaw. Imo it is an option and good to have in the bag for certain situations. Imo the too big tk backs are more of a problem to use and correct...especially for serve rtns. I'd recommend he learn to just modify this tk back a bit to round out the back edge a bit when he has time, but allow the straight back in time crunch situations. you find the loop growing a bit when he has more time and comfort playing. I don't think what he is doing actually contains the negative issues you lump in with it.

After watching his tournaments, that's the conclusion I came to. In training he has a smile on his face, and rips balls with all his effort from a very short straight-back take-back. In training they go in much of the time. In pressure situations, he doesn't "go for it", yet he swings from the same hip position. This leads to a lot of short balls. My verdict is that he needs a more fluid swing for easy power.... but your idea to slightly modify his existing stroke might end up being more practical.

 

[LeeD]

Don't blame his swing, it's his mental outlook, afraid to hit when there is pressure.
Connors, McEnroe, had straight takebacks. Sure, they choke at times, but choking is MENTAL, not physical.
Best WTA forehand beside's Graf was AnkeHuber's straight takeback.
Monica Seles had straight takeback, along with Everts, Austin.
Once again, when you tighten up and CHOKE, it's nothing to do with your strokes, it's everything to do with your mental state.

 

[Bendex]

Don't blame his swing, it's his mental outlook, afraid to hit when there is pressure.
Connors, McEnroe, had straight takebacks. Sure, they choke at times, but choking is MENTAL, not physical.
Best WTA forehand beside's Graf was AnkeHuber's straight takeback.
Monica Seles had straight takeback, along with Everts, Austin.
Once again, when you tighten up and CHOKE, it's nothing to do with your strokes, it's everything to do with your mental state.

You're right about his mental state, I counsel him often about it. In my opinion, an easy power forehand is the better option for someone his age to learn, for a variety of reasons. He also has a good natural throwing motion when he throws a ball, so he may as well take advantage of it. It's hard to imagine a straight back swing being able to dominate the ball on our bouncy blue courts of death (where tournaments are played).