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[uspta146749877]

Linear momentum

Thanks. First I need to check those references from the ITF book. Regards, Don

There is a full chapter ( 3 ?) on this subject


There are 3 possible issues to address:

1.a choice between an open stance and square stance for
modern forehand

2.a decomposition of forehand into
a) linear movement
b) angular movement
c) brushing/lifting movement

3.conversion of energy between LINEAR MOVEMENT and
ANGULAR MOVEMENT

See as well

http://tt.tennis-warehouse.com/showthread.php?p=2504965#post2504965

[uspta146749877]

brushing movement

John,

Linear momentum in the forehand is considered significant by some and also crops up in threads as you probably know. Do you have any views on this and are there any articles which support the 'linear plus angular' concept? Once the forehand is in motion I only see angular momentum and torque.

Don

There is brushing/lifting movement as well -see Nadal

[kvh2000]

coria's serve

John... I think it would be fascinating if you were to review coria's current strokes versus how he was hitting before he became, in his own words, "lost on the wrong road....without a map".

Perhaps an analysis of his serve by you would even get the magician back on track!

kurt

[johnyandell]

Haven't seen him play much less filmed him since before that French Open final. I suspect though that you wouldn't see technical problems. I think the issues are probably mainly emotional for him. If he makes it in front of the camera somewhere where we are filming I'll take a look.

[kvh2000]

coria

yeah John, I agree that it is probably a mental more than a technical thing, but in his latest match (on clay vs. schwank in stuttgart) he double faulted 19 times! (scores were 0-6,6-1,6-2).....there must be something technically wrong there as well....

kurt

[johnyandell]

Like I said I wouldn't necessarily agree. The mind can easily have that type of effect. If he comes across a court where we're filming we can check.

[uspta146749877]

A reference text

Thanks. First I need to check those references from the ITF book. Regards, Don

Any luck with a getting a reference text?

[emeralda]

References

Thanks for the additional comments. 'Biomechanical Principles of Tennis Technique' and the ITF book are accessible but I don't have yet.

[uspta146749877]

Please stay in touch

Thanks for the additional comments. 'Biomechanical Principles of Tennis Technique' and the ITF book are accessible but I don't have yet.

Please stay in touch

[emeralda]

From the ITF book.
"...forward linear momentum is crucial in the development of racquet head speed"
"forward movement of the trunk increases the linear velocity of the shoulder and also helps in pre-stretching the shoulder musculature."
"...it appears square stance stokes can create slightly higher racquet head speeds" (about 1 m/s for professionals, 21.2m/s to 22.3m/s)

So forward linear momentum is crucial yet the increase in the racquet head speed is minimal and the authors do not make a definitive commitment to open or square stance.

[uspta146749877]

From the ITF book.
"...forward linear momentum is crucial in the development of racquet head speed"
"forward movement of the trunk increases the linear velocity of the shoulder and also helps in pre-stretching the shoulder musculature."
"...it appears square stance stokes can create slightly higher racquet head speeds" (about 1 m/s for professionals, 21.2m/s to 22.3m/s)

So forward linear momentum is crucial yet the increase in the racquet head speed is minimal and the authors do not make a definitive commitment to open or square stance.

Don,
please see
a very simple quotation from Page 66 of the same book-
"Open stance forehands have been shown to have court coverage and other
tactical advantages"
I believe that recovery time for open stance is smaller.
See

http://www.tennisplayer.net/members/footwork/michael_friedman/michael_friedman_hitting_stance_images/michael_friedman_hitting_stance.html

See as well

http://www.tennisplayer.net/members/biomechanics/John_Yandell/Comparing_Open_Closed_Stances/Comparing_Open_Closed_Stances.html

See as well the middle part of Page 68 for comments related to your post
regards,
julian usptapro 27873

[emeralda]

Don,
please see
a very simple quotation from Page 66 of the same book-
"Open stance forehands have been shown to have court coverage and other
tactical advantages"
I believe that recovery time for open stance is smaller.
See

http://www.tennisplayer.net/members/footwork/michael_friedman/michael_friedman_hitting_stance_images/michael_friedman_hitting_stance.html

See as well

http://www.tennisplayer.net/members/biomechanics/John_Yandell/Comparing_Open_Closed_Stances/Comparing_Open_Closed_Stances.html

Speed numbers quoted above are twice higher than in the ITF book-
hard to understand why.Maybe JY knows why
See as well the middle part of Page 68 for comments related to your post
regards,
julian usptapro 27873

Julian,
Quotes from

http://www.tennisplayer.net/members/...d_Stances.html

"For the professional players, the actual racquet head velocity for the open stance was about 47mph. For the closed stance it was about 50mph"

"These are relatively small differences, about 5%. They were less than the error factor in the measurements..."

My enquiry may be unrealistic as I was considering a 'standard' topspin FH with time not a factor and then comparing stances from a purely technical perspective. Is there a preferred stance?
You have shown forward linear momentum is defined and described but if the racquet head speeds are as stated then the benefits of forward linear momentum may be over-stated.
Regards,
Don

[uspta146749877]

Open stance is preferable

Julian,
Quotes from

http://www.tennisplayer.net/members/...d_Stances.html

"For the professional players, the actual racquet head velocity for the open stance was about 47mph. For the closed stance it was about 50mph"

"These are relatively small differences, about 5%. They were less than the error factor in the measurements..."

My enquiry may be unrealistic as I was considering a 'standard' topspin FH with time not a factor and then comparing stances from a purely technical perspective. Is there a preferred stance?
You have shown forward linear momentum is defined and described but if the racquet head speeds are as stated then the benefits of forward linear momentum may be over-stated.
Regards,
Don

Don,
Open stance is PREFERABLE for me because a QUICKER RECOVERY time
regards,
julian

[emeralda]

Don,
Open stance is PREFERABLE for me because a QUICKER RECOVERY time
regards,
julian

OK, fair enough. Thanks also for all the references. I've been curious about this subject since my junior days where I survived with a less than average FH.

[uspta146749877]

Sorry

OK, fair enough. Thanks also for all the references. I've been curious about this subject since my junior days where I survived with a less than average FH.

Sorry that you are disappointed by my answers