Single handed backhand for juniors... - Page 10

rkelley · 11-26-2012, 12:24 PM

Quote:

Originally Posted by julian

Greetings,
1.Let say that the backhand is modeled after
http://www.youtube.com/watch?v=lPBM-hE1Dhw

2.Let me rephrase your question if I may-
what is a speed of the racket head AT THE CONTACT for the model described by the LINK ABOVE
what is a possible racket head speed at the contact for the above video?
3.The link above does NOT stress the RADIUS VARIABLE

The link is Djokovic hitting his bh. He's got a great bh, but I don't see how this video address the question of maximum possible speed at contact. What am I missing?

kopfan · 11-26-2012, 12:42 PM

Some say 1hbh have disadvantages while returning serves. I use 1hbh and see this issue mainly with bigger and hh racquet user only. When using a mid or smaller head and very hl, there is lot of time to move the racquet to hit, push or slice return of serve. Plus.. there is a further reach point on wide bh serve return. 1hbh need a faster footwork to make up the slower time to prep for a shot.

bhupaes · 11-26-2012, 12:58 PM

Quote:

Originally Posted by rkelley

The link is Djokovic hitting his bh. He's got a great bh, but I don't see how this video address the question of maximum possible speed at contact. What am I missing?

The thing about the 2HBH is that it recruits the same group of muscles as the FH, and uses similar body kinetics. If you look at Joker's left hand in the 2HBH video (posted by Julian), it resembles a Type 3 FH (as in the blog.tennisspeed.com thread).

For whipping a 1HBH, I believe the main action comes from the deltoids and external shoulder rotation.

Neither, if executed correctly, requires a huge backswing. So I guess it comes down to the qualities of these two different groups of muscles. I don't know for sure, but if I had to bet on something, I would choose the 2HBH for RHS.

julian · 11-26-2012, 02:13 PM

Quote:

Originally Posted by rkelley

The link is Djokovic hitting his bh. He's got a great bh, but I don't see how this video address the question of maximum possible speed at contact. What am I missing?

Let me provide a "partial" reference.
The title of THIS POST should be corrected as "A table of data"
Sorry
regards,
Julian

BIOMECHANICAL ANALYSIS OF TOP TENNIS PLAYERS
Gideon Ariel, Ph.D.1 , Vic Braden1, Ann Penny1, John Probe1 ,Rudolf Buijs1
and Alfred Finch2
1Institute for Biomechanical Research, Coto Research Center, Coto De Caza California,
2Indiana State University, Terre Haute, Indiana, USA
The purpose of this paper was to perform kinematic analyses of some of the top players
in the World during a major competition using multiple view video images that were
transmitted and digitized over the Internet. Backhand and serve stroke data for Federer;
Clijsters, and Aggasi were selected for the present study.
KEY WORDS: elite tennis players, tennis biomechanical analysis, Internet analysis

http://www.arielnet.com/start/apas/s.../toptennis.pdf
Please note that data are in KILOMETERS per HOUR,NOT MILES PER HOUR
Some data around the contact are a bit suspect-I can elaborate but it will be a long one.
Basically the quoted paper was NOT peer reviewed.
There were some comments by Systemic Anomaly about this paper.
Going back to your original question

The best is to LOAD the pdf document specified in the link above
Basically three important numbers for backhands are
125 vs 83 vs 96.6
for Federer vs Clijster vs Agassi
---> the "clumsy" table

Table 1 Linear velocities of the hand, tip of the racket and ball velocities prior to and
after impact with the ball (km*hr-1) and the peak racquet angular velocity

Player Strokes Hand Prior Hand Tip Prior
Agassi Backhand 22.5 28.3 96.6 ...
Clijsters Backhand 27.4 27.2 83.4 ...
Federer Backhand 125.2 ...

julian · 11-26-2012, 02:30 PM

Quote:

Originally Posted by bhupaes

The thing about the 2HBH is that it recruits the same group of muscles as the FH, and uses similar body kinetics. If you look at Joker's left hand in the 2HBH video (posted by Julian), it resembles a Type 3 FH (as in the blog.tennisspeed.com thread).

For whipping a 1HBH, I believe the main action comes from the deltoids and external shoulder rotation.

Neither, if executed correctly, requires a huge backswing. So I guess it comes down to the qualities of these two different groups of muscles. I don't know for sure, but if I had to bet on something, I would choose the 2HBH for RHS.

****deleted***

rkelley · 11-26-2012, 02:50 PM

Quote:

Originally Posted by julian

http://www.arielnet.com/start/apas/s.../toptennis.pdf

I couldn't get this link to work.

julian · 11-26-2012, 03:32 PM

Quote:

Originally Posted by rkelley

I couldn't get this link to work.

It is my fault.Sorry.
Please try the string between quotes
"www.sportsci.com/start/apas/studies/toptennis.pdf"
Sorry again
Please let me know whether it does work

rkelley · 11-26-2012, 05:12 PM

Quote:

Originally Posted by julian

It is my fault.Sorry.
Please try the string between quotes
"www.sportsci.com/start/apas/studies/toptennis.pdf"
Sorry again
Please let me know whether it does work

Thanks. I got it.

I'll say that some of the values in the paper don't seem quite right. The serve numbers look particularly strange. Looking at the table, the ball before contact on a serve is moving at 47 and 22 kph (42 ft/s and 20 ft/s) for Clijsters and Fed respectively. That's a mighty high toss if that number is supposed to be right before impact. After impact Fed's serve is 141 kph (88 mph). That's a tad on the slow side for the men's game, especially if it was a first serve.

All that said, the numbers in the article for the backhand would seem to support my position that higher racquet head speeds are achievable with a 1hbh. As you noted in your previous post Fed (1hbh) had the highest tip velocity before impact of the three players (125 vs 83 vs 96.6 for Federer vs Clijster vs Agassi).

So, am I missing something?

Netspirit · 11-26-2012, 07:39 PM

I hit 1HBH, I like the shot and I am not switching.

However, I am teaching my kid 2HBH. One must be insane not to - considering that all top 1HBH pros (Federer, Youzhny, Haas, Kohlschreiber, Wawrinka, Almagro) were taught in 80s, they are currently in their late 20s / early 30s and are quickly approaching retirement.

1HBH is dead, just like the Continental forehand grip.

julian · 11-27-2012, 06:44 AM

Quote:

Originally Posted by rkelley

Thanks. I got it.

I'll say that some of the values in the paper don't seem quite right. The serve numbers look particularly strange. Looking at the table, the ball before contact on a serve is moving at 47 and 22 kph (42 ft/s and 20 ft/s) for Clijsters and Fed respectively. That's a mighty high toss if that number is supposed to be right before impact. After impact Fed's serve is 141 kph (88 mph). That's a tad on the slow side for the men's game, especially if it was a first serve.

All that said, the numbers in the article for the backhand would seem to support my position that higher racquet head speeds are achievable with a 1hbh. As you noted in your previous post Fed (1hbh) had the highest tip velocity before impact of the three players (125 vs 83 vs 96.6 for Federer vs Clijster vs Agassi).

So, am I missing something?

Answering your last question:
Djokovic generates much higher racket head speed than Clijster and Agassi

rkelley · 11-27-2012, 07:20 AM

Quote:

Originally Posted by julian

Answering your last question:
Djokovic generates much higher racket head speed than Clijster and Agassi

OK. That's fine as long as we both realize that we're still back to one opinion verses another. Heck, I could be wrong, I'll admit that.

julian · 11-27-2012, 07:31 AM

Quote:

Originally Posted by rkelley

OK. That's fine as long as we both realize that we're still back to one opinion verses another. Heck, I could be wrong, I'll admit that.

rkelley,
I will provide a quote from Knudson as well about 1hbh speeds vs 2hbh speeds.
I just need couple of hours.
Please try to see that everything in US takes time.
We are sitting on the cliff.
I hope you are NOT in US.
I assume you have his book

I am in a bit difficult situation because I am the party providing links and data.
If you have any data about speeds for backhands you are welcome to provide.
If you prefer an E-mail my E-mail address provided in my signature below.
The state of opinions in US is that the speed of backhand by Djokovic is around the speed of his LEFT HANDED FOREHAND.
regards,
Julian

julian · 11-27-2012, 08:27 AM

"In the recent study of college players,there was no difference in raquet speed at impact between backhand techniques and BOTH Backhand used ..."
Biomechanical Principles of Tennis Technique"
Dave Knudson 2006 Page 101
Dave Knudson,I believe,is quoting
Reid Machar and Bruce Elliot (2002) .The one- and two-handed backhands in tennis
Sports Biomechanics,1,47-69
Couple of simple comments:
1.I do NOT have an access to the quoted paper by Machar and Elliot
2.Other pertinent references are
1) Elliott, B. C., Marsh, A. P. & Overheu, P. R. (1989). The topspin backhand drive in tennis: a biomechanical analysis. Journal of Human Movement Studies, 16, 1-16.
2) Groppel, J. L. (197

. Kinematic analysis of the tennis one-handed and two-handed backhand drives of highly-skilled female competitors. Thesis (Ph.D.), Florida State University.
3) Groppel, J. L. (1992). High Tech Tennis. Champaign, IL: Leisure Press.
4) Patterson, J. (1976). How to hit two-handed backhands. Tallahasse, FL: A. B. Dick.
5) Reid, M. M. & Elliott, B. C. (2001). The One-and Two-Handed Backhands in Tennis. Journal of Sport Biomechanics, In press.
6) Schonborn, R. (199

. Advanced training techniques for competitive players. Meyer & Meyer Verlag, Aachen, Germany.
7) Wang, L-H., Wu, H. W., Su, F. C. & Lo, K. C. (199

. Kinematics of the upper limb and truck in tennis players using single-handed backhand strokes. In H. Riehle, & M. Vieten (eds.), ISBS XVI (pp.273-275). Taiwan: University of Konstanz.

julian · 11-27-2012, 11:20 AM

Sports Biomech. 2002 Jan;1(1):47-68.
The one- and two-handed backhands in tennis.
Reid M, Elliott B.
Source

International Tennis Federation, London, UK.
Abstract

The study investigated differences in the one- (SH) and two-handed (DH) backhands when hit flat, across-court (AC) and down-the-line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college-level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high-speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement).

Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique.

The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1 degrees; DH: 83.4 degrees) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m: DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m: DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s: DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique.

boramiNYC · 11-27-2012, 11:30 AM

nice study but mostly easily predictable findings I think. one question. "delayed the horizontal acceleration of the racquet towards the ball" could you explain?

julian · 11-27-2012, 11:32 AM

Please click
https://ojs.ub.uni-konstanz.de/cpa/a...File/3426/3225
If the link does NOT work please let me know

julian · 11-27-2012, 11:35 AM

Quote:

Originally Posted by boramiNYC

nice study but mostly easily predictable findings I think. one question. "delayed the horizontal acceleration of the racquet towards the ball" could you explain?

Quote from the article
"Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique."
How would you easy predict that speeds are "COMPARABLE"?
Does rkelley agree with you?

julian · 11-27-2012, 11:42 AM

Quote:

Originally Posted by boramiNYC

nice study but mostly easily predictable findings I think. one question. "delayed the horizontal acceleration of the racquet towards the ball" could you explain?

It is possible that results are so "easily predictable" that they are NOT TRUE
See the title of the post

boramiNYC · 11-27-2012, 11:52 AM

Quote:

Originally Posted by julian

Quote from the article
"Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique."
How would you easy predict that speeds are "COMPARABLE"?
Does rkelley agree with you?

because rally shots and hardest hit shots by both are pretty comparable in a competitive match of pros.

julian · 11-27-2012, 01:12 PM

Quote:

Originally Posted by boramiNYC

because rally shots and hardest hit shots by both are pretty comparable in a competitive match of pros.

Just to make sure that we are on the same page
The TENNIS Channel provides a value of a speed of ball
The paper above refers to "racquet horizontal velocities".
The word velocity refers to a velocity a tip of a racket.
If my remark is too trivial I apologize.

11-27-2012, 08:27 AM	#193
julian Professional Join Date: Dec 2006 Location: Bedford,Massachusetts,US Posts: 1,404	A quote by Knudson-1hbh vs 2hbh "In the recent study of college players,there was no difference in raquet speed at impact between backhand techniques and BOTH Backhand used ..." Biomechanical Principles of Tennis Technique" Dave Knudson 2006 Page 101 Dave Knudson,I believe,is quoting Reid Machar and Bruce Elliot (2002) .The one- and two-handed backhands in tennis Sports Biomechanics,1,47-69 Couple of simple comments: 1.I do NOT have an access to the quoted paper by Machar and Elliot 2.Other pertinent references are 1) Elliott, B. C., Marsh, A. P. & Overheu, P. R. (1989). The topspin backhand drive in tennis: a biomechanical analysis. Journal of Human Movement Studies, 16, 1-16. 2) Groppel, J. L. (197. Kinematic analysis of the tennis one-handed and two-handed backhand drives of highly-skilled female competitors. Thesis (Ph.D.), Florida State University. 3) Groppel, J. L. (1992). High Tech Tennis. Champaign, IL: Leisure Press. 4) Patterson, J. (1976). How to hit two-handed backhands. Tallahasse, FL: A. B. Dick. 5) Reid, M. M. & Elliott, B. C. (2001). The One-and Two-Handed Backhands in Tennis. Journal of Sport Biomechanics, In press. 6) Schonborn, R. (199. Advanced training techniques for competitive players. Meyer & Meyer Verlag, Aachen, Germany. 7) Wang, L-H., Wu, H. W., Su, F. C. & Lo, K. C. (199. Kinematics of the upper limb and truck in tennis players using single-handed backhand strokes. In H. Riehle, & M. Vieten (eds.), ISBS XVI (pp.273-275). Taiwan: University of Konstanz. Last edited by julian : 11-27-2012 at 08:33 AM.

11-27-2012, 11:20 AM	#194
julian Professional Join Date: Dec 2006 Location: Bedford,Massachusetts,US Posts: 1,404	Data Sports Biomech. 2002 Jan;1(1):47-68. The one- and two-handed backhands in tennis. Reid M, Elliott B. Source International Tennis Federation, London, UK. Abstract The study investigated differences in the one- (SH) and two-handed (DH) backhands when hit flat, across-court (AC) and down-the-line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college-level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high-speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1 degrees; DH: 83.4 degrees) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m: DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m: DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s: DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique. Last edited by julian : 11-27-2012 at 11:33 AM.

11-27-2012, 11:32 AM	#196
julian Professional Join Date: Dec 2006 Location: Bedford,Massachusetts,US Posts: 1,404	Double-handed backhand down the line vs cross court Please click https://ojs.ub.uni-konstanz.de/cpa/a...File/3426/3225 If the link does NOT work please let me know Last edited by julian : 11-27-2012 at 11:43 AM.

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