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J. Landlinger et al.
Journal of sports science and medicine (2010)9, 643-651
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Racquet speed is the players weapons intennis.
Inefficient motions and positions of variousjoints can either be detrimental to speed
and the spin of the ball or may increase the
risk of injury.
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There is no study comparing proximal-to
distal sequencing patterns of the
forehand with respect to elite vs. high
performance playing levels.
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To identify and compare key mechanical
features and their timing of forehand
groundstrokes between ATP-professionals(elite) and high performance (HP) youth
players when shots were played cross
court and down the line.
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ParticipantsAll male
Elite(Mean)
HighPerformance
(Mean)
Ranking ATP 347 Junior top 15
Age 23 16.3
Weight 78.2 72.8
Height 188.1 185.9
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Testing procedure:
Hit as many practice strokes as needed with the
same velocity and action as they would in the
match.
Use their own racquets.
Ball machine controlled pre-impact ball
horizontal velocity (20 m.s) and trajectory.
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2 series of 10 forehands cross court and
down the line (4 X 10 strokes) to a target
area (randomized order).
No instructions in terms of foot placement.
2 minutes break after each series.
6 fastest shots of each (= 12 strokes) wereused.
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Data Collection: 39 reflective markers were placed on bony
landmarks (Plug-in Gait Marker Set, Vicon
Peak, Oxford, UK).
4 markers (14 mm in diameter) were placed
on the racquet of each subject (racquet
head, shaft, at 3 and 9 oclock positions).
Participants wore tight shorts, no shirts.
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Data collection (cont.)
8 Vicon MX 13 cameras (Vicon Peak, Peak,
Oxford, UK) sampling at 400 Hz.
Cameras were positioned around one side of
the court;
3 behind the baseline
3 overhead cameras on a traverse at 4m height
in front of the player
The centre of baseline were used as theorigin of the global coordinate system.
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Data collection (cont.)
Y-axis
pointing forward to the net
X-axis positive to the right
Z-axis vertical
All 43 markers were reconstructed withthe Nexus software (Nexus 1.3, Vicon,
Oxford, UK), data were filtered with a
Woltring filter (MSE of 10).
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Data was analyzed during the forwardswing of the stroke.
Impact was the point where the firstball/racquet contact occurred.
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Descriptive statistics
Two-way ANOVA with repeated
measures
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Mean forward swing time of tennis forehanddid not vary between elite (0.324+ 0.086) andHP (0.326 + 0.064).
In the down the line situation, both groupsrotated their hips and racquets furtherbackwards (p
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The timing of peak angles help facilitate the
forward swing in the tennis forehand.
The hips must have started the counter-clockwise rotation towards the ball earlier than
the shoulders.Peak angular racquet rotation demonstrates
that the racquet tends to lag behind.
Extended wrist(55 milliseconds beforeimpact)should have put additional stretch onthe forearms to help generate wrist andracquet speed.
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To improve the forehand performance
level, the main 3 things to focus are;
Pelvis
Trunk rotation velocity
Their timing
A good rear leg drive will initiate pelvis
rotation, consequently, increase theseparation angle.
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Tanaporn Panich
53910313
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