1

Hello again!  Been working on my strokes, and am getting better (I think) at using Kinovea for analysis.

Figured out that I could trace the swing path and track hand and racquet head speed:

[video]http://youtu.be/di5YjeWm-7s[/video]

2

Still frames with tracking of the swing paths seem very useful.
http://img.photobucket.com/albums/v65/gregolas/Tennis/JointItem413-00000866ffthru_zps204178d6.jpg

3

Overlaying pictures to compare with a pro stroke:
http://img.photobucket.com/albums/v65/gregolas/Tennis/greggrigoroverlay1_zpsf8251d60.jpg

4

Wonder if there are any good suggestions on how to track shoulder/hip rotation, which would be very useful.  Arm-racquet angle too.  Perhaps a wire frame skeleton which we could align to certain points and track?  smile

5

Greg,. im a novice,but improving user,. may I ask how you got the rackets speed?

6

Hi pgendreau,
Be aware that you cannot really make speed measurements as in post #2 unless the various points of the trajectory are all on the same plane and this plane is perpendicular to the camera optical axis.

Tennis serve and stroke have many rotational component, it will be impossible to measure this in a 2D software. You may get better results with a pure side view.

7

Hi Joan,

Yes, I know the speeds won't be very accurate, but the information is still useful for demonstrating things like the relative speed of the hand vs the racquet tip, among other things.

pgendreau, you have to set the frame rate in the software, and calibrate distance with an item of known length ( I use the racquet @ 27 inches).  Then when you track something, you can add speed as a label.  I hope I didn't forget anything...

8

Greg, what camera are you using to do your filming?

9

Sorry for the late reply!  I use a Casio FC-150.