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julian
01-24-2012, 01:11 PM
An abstract of an interesting paper
A title of the post was cut off a bit-sorry

Sports Biomech. 2010 Nov;9(4):280-95.
Kinematic differences of elite and high-performance tennis players in the cross court and down the line forehand.
Landlinger J, Lindinger SJ, Stöggl T, Wagner H, Müller E.
Source

Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria. landlinger_johannes@hotmail.com
Abstract

This study identified and compared the full body kinematics of different skill levels in the forehand groundstroke when balls were hit cross court and down the line. Forty-three three-dimensional retroreflective marker trajectories of six elite and seven high-performance players were recorded using an eight-camera 400 Hz, Vicon motion analysis system. The six highest horizontal velocity forehands with reliable kinematics of all participants were analysed for each specific situation (a total of 156 analysed shots). Significant differences (p < 0.01) and large effect sizes were observed between elite and high-performance players in linear velocity of the shoulder (2.0 vs. 1.2 m/s), angular velocity of the pelvis (295 vs. 168 degrees/s), and angular velocity of the upper trunk (453 vs. 292 degrees/s) at impact. The elite group showed a tendency towards higher racquet velocities at impact (p < 0.05). No significant differences were found in angular displacement of the racquet, hip alignment, or shoulder alignment at the completion of the backswing; nor did angular displacement vary significantly at impact. Irrespective of the group, different shoulder, hip, and racquet angles were found at impact, depending on the situation. The results should assist coaches when striving to improve their players' forehand.

Limpinhitter
01-24-2012, 02:01 PM
Fascinating! John Yandell should like this.

Missing, however, is the issue of the balance, timing and coordination needed to control the various aspects of added velosity among the "elite" players. Isn't that the critical difference between elite and high level players?

PS: Could you please provide a link to this abstract?

julian
01-24-2012, 03:42 PM
Fascinating! John Yandell should like this.

Missing, however, is the issue of the balance, timing and coordination needed to control the various aspects of added velosity among the "elite" players. Isn't that the critical difference between elite and high level players?

PS: Could you please provide a link to this abstract?

Link
http://www.ncbi.nlm.nih.gov/pubmed/21309302

Ducker
01-24-2012, 10:15 PM
I read that, It basically reads: Top elite players swing harder and faster than none elite players.

I could of told you that and I didnt setup a study...lol

spacediver
01-24-2012, 11:21 PM
Just skimmed the article - there's a lot more to it than what's evident in the abstract. Some good stuff, and the authors seem to know their tennis well.

julian
01-25-2012, 08:33 AM
Fascinating! John Yandell should like this.

Missing, however, is the issue of the balance, timing and coordination needed to control the various aspects of added velosity among the "elite" players. Isn't that the critical difference between elite and high level players?

PS: Could you please provide a link to this abstract?

See as well
http://www.jssm.org/vol9/n4/15/v9n4-15text.php

julian
01-25-2012, 08:46 AM
Just skimmed the article - there's a lot more to it than what's evident in the abstract. Some good stuff, and the authors seem to know their tennis well.

Other papers by the same author
· Key factors and timing patterns in the tennis forehand of different skill levels. Journal of Sports Science and Medicine, 9, 643-651. [Landlinger, J., Lindinger, S., Stöggl, T., Wagner, H., & Müller, E.] [2010]
· Differences in ball speed and accuracy of tennis ground strokes between elite and high performance players. European Journal of Sport Science, accepted. [Landlinger, J., Stöggl, T., Lindinger, S., Wagner, H., and Müller, E.] [2011].
· Neglected Armschnelligkeit. Tennis, 5, 14-18. [Landlinger, J.] [2006]
· Development of a tennis specific speed tests for arm movement. In: K. Weber et. al. (Eds.), Research Transfer to the practice of sports games, pp. 341-347. Cologne, Germany: Sportverlag Strauss [Landlinger, J. Benko & U.] [2006]

JohnYandell
01-25-2012, 09:46 AM
One really interesting question would be if there were significant differences in the angle of the wrist to the forearm between the crosscourt and d the l. Don't have time to dig in. Anyone else have an answer?

Other questions--where on the court and at what height was the ball struck and was the ball essentially the same in speed, depth, height for all the crosscourts, and was it the same or diffferent for d the l?

5263
01-25-2012, 10:01 AM
Yes, lots of variables to account for.

dennis10is
01-25-2012, 10:39 AM
Yes, lots of variables to account for.

Were they able to record attribute of the balls before they were struck? If they did, they could have compared the two groups of ball for each group (elite vs high performance) to see if the fed balls were from the same "population" across skill levels.

spacediver
01-25-2012, 10:55 AM
One really interesting question would be if there were significant differences in the angle of the wrist to the forearm between the crosscourt and d the l. Don't have time to dig in. Anyone else have an answer?

Other questions--where on the court and at what height was the ball struck and was the ball essentially the same in speed, depth, height for all the crosscourts, and was it the same or diffferent for d the l?

I can try to answer your questions properly later, but for now, it appears as if there were no significant differences in wrist extension angle at impact between dtl and crosscourt, across both groups. See table IV of article.

spacediver
01-25-2012, 10:57 AM
Were they able to record attribute of the balls before they were struck? If they did, they could have compared the two groups of ball for each group (elite vs high performance) to see if the fed balls were from the same "population" across skill levels.


"Since a ball machine controlled pre-impact ball horizontal velocity (20m/s), direction, and trajectory for the participants, they were given as many practice strokes as desired to become accustomed to the situation on court. The ball machine projected the new tennis balls down the line when participants had to play cross court and vice versa. Starting at the baseline, subjects were instructed to hit two series of 10 forehands crosscourt and down the line (4 X 10 strokes) to a target area. They were encouraged to hit the ball with the same velocity and action as they would in a match. No instructions were given in terms of foot placement (stance). After each series, subjects had a two-minute break, in particular to keep motivation and oncentration levels high. The six fastest cross court and down the line shots performed by 13 subjects with reference to horizontal racquet head speed (156 forehand strokes) were chosen for the analysis."

dennis10is
01-25-2012, 01:11 PM
"Since a ball machine controlled pre-impact ball horizontal velocity (20m/s), direction, and trajectory for the participants, they were given as many practice strokes as desired to become accustomed to the situation on court. The ball machine projected the new tennis balls down the line when participants had to play cross court and vice versa. Starting at the baseline, subjects were instructed to hit two series of 10 forehands crosscourt and down the line (4 X 10 strokes) to a target area. They were encouraged to hit the ball with the same velocity and action as they would in a match. No instructions were given in terms of foot placement (stance). After each series, subjects had a two-minute break, in particular to keep motivation and oncentration levels high. The six fastest cross court and down the line shots performed by 13 subjects with reference to horizontal racquet head speed (156 forehand strokes) were chosen for the analysis."

OK, thanks.