as you have said, I think there are portable devices that can be used.

Hi Henk.

Thanks for your idea.

Hi Sunday

Do you know some of these indoor devices? Did you used it?.

Thanks for your help

Raúl

Hola Raúl,

I have not use it myself (will do it soon), but FC Barcelona uses it with good results:

http://statsports.com/

I hope it helps!

Saludos,

Ferran

I think this will help you. https://www.iis.fraunhofer.de/en/ff/lok/proj/redfir.html

Hi Raúl

There are plenty of options for indoor tracking such as: 

i) http://kinexon.com/

ii) www.catapultsports.com/system/indoor/

iii) https://www.zebra.com

Best,

Hi Raul,

Very clever solution is GPSport system (combination of indoor GPS system with the 3D accelerometers). We solve similar problem for the volleyball match by 3D vide analysis system. It is much more work with it, but you can solve not only distance but vertical movement too.

Frantisek

Automatic tracking system

Thank's Ferran, is a good option for outdoor.

Please, let me know when you are going to use it and I will go for help (or see) you;)

Raúl

Thanks Siby. Is also a good idea for some sports.

Hi Pedro Tiago. Kinexon it seem to me is like a gold standar. That device has been used by you?

Thanks in advance

Dear František

It could be a good idea because we have some IMU's and the GPS combination could be an option. Have you some paper or did you write some about it?

Thank you very much

Raúl

Hi João.

Thank you for your always kind help.

im not sure what useful data we can get from knowing, there are so many variables, can one extrapolate or make any meaningful conclusions that will help your athlete?

correlation is not necessarily causation.

Hi Raúl

I have never used it but I must say I know the equipment fair well. They use RFID  technology that has been very popular lately. I think you should take a decision based on your available financial resources and the reliability and usability of the system. there are many options.

Best,

If is just about distance, a device with a pedometer incorporated would be enough. Or not?

The Garmin Fenix 3 or 5 is capable to measure the distance without GPS. Before the match the player has to use it for a while to learn (the watch) the rhythm, cadence, ferquencie, step length of him or her. After that it can calculate the distance. Moreover it has a strong antene to measure the distance with gps across slim roofs aswell.

Ted is rigth, but the mentioned watch is good for this one too (with the running belt), because it will measure the times of touch down phases and the times of the flight phases too... therefoe the dynamics of the movement are covered

Dear Raul,

the easiest and cheepest (and in my eyes the most accurate) way is to use accelerometry on an estimated  center of gravity (COG). However, as already indicated by Ted and Béres (but probably not clearly stated), you have to take the orientation of the local coordinate system of the acceleration sensor related to the global coordinate system into account (as I suppose you only want to have the 2D movement data). Guess that the acceleration along the z-axis must not necessarily direct in the vertical direction, e.g. when the orientation is titled by 90° in any direction due to  trunk flexion. But this can be done by a transformation matrix, however you need to calibrate the sensor position prior to your measures, to be able to recalculate the  position and orientation by double integration.

If done so, you can get a quite good movement profile of your athletes. But consider, the COG is only an estimation. Probably a preliminary comparative kinematic study would shed some light into the accuracy of this method.

Hope this answer helps you for your methodological considerations.

Hi Ralph. I will like to know how quantifying player’s load on a real match. We are trying to know the individual affectation of a game to each player.

Hi Pedro. You are right about decision and financial resources. It’s not easy jet now. Thanks for your help.

Dear Cristiana. I have never seen to quantifying “not normal” gait patterns. I will look for information on this.

Hi Béres. Good idea is yours. We have to fight with others variables on a real match context (coaches, time, referees…). Thanks for your time.

Dear Ted. Distance covered couldn’t be the best indicator. We have seen some papers to quantify load players (for tennis players I think) that used to do an accelerometer and a vector’s information of X, Y and Z with a resultant named “arbitrary units”. We are thinking in something like that for 2 reasons. 1) We have triaxial accelerometers. 2) Players could wear it during the match. I know that you are quite familiar with this data processing. Is it possible to know in an individualized way, the loading of the same party for 2 different subjects?. Thank you very much for your help.

Dear Jakob. I think accelerometer could be the best option too. I also think that the accelerometer is the best option. It is now necessary to find out the methodology to be used for the study.

Seriously, thank you all for your contributions

Raul, 

We have measured body displacements on soldiers using the Microgaite Gyko: www.gyko.it. This is an accelerometer, gyroscope and magnetometer; it can be attached to most body segments including L-Spine or T-Spine. 

I am not sure how much literature there is as this is a fairly new instrument but you can try DOI 10.3389/978-2-88919-614-2

I know, I appreciate your problem, Raul; as an ex-player I also had the same problem.

A Reliance On Science Produces Not Giants

Do you remember those legends of old? The ones who raised the level of their sport to an art form. The ones who used sticks rather than steel. The ones who drank water from a tap rather than a formulated liquid from a bottle.

Do you remember those giants?

And if you had today’s players play with their unscientific equipment, would they play as well?

In fact, do today’s players with their scientific equipment play as well as they did?

The athlete has lost his way. He is no longer seen as a human being. Rather he is seen as a skin-enclosed sack of dissectible parts. His brain is imaged. His muscles are torn. His saliva is screened. His movements are filmed.

He has been taken from his field of play and locked within the clear plastic of a petri dish. He was once a free man that roamed the verdant fairways. He was once a free man who loved the sound of his skates scraping the ice. He was once a free man who played with a racquet and ball.

Instead of roaming fairways he now roams the polished floors of ivory towers. Instead of hearing the scratch of skates against ice he now hears the high-pitched sounds of beeping machines. Instead of holding a racquet he now holds an electronically studded wand.

If one wishes to add a semblance of legitimacy to his argument he need only begin his statement with, “The science says . . .” Science has become the answer to everything. And this is because the wrong questions are being asked.

If an athlete is in the zone, does he care what parts of his brain lights up on the MRI? If he hits a powerful drive does it matter what his swing speed was? If he hits a perfect fade does it matter what his path to face ratio was?

Have machines provided a greater understanding into the nature of how instruments work? Yes.

Have they provided a greater understanding of ball flights and ball-club interactions? Yes.

Have they provided a greater understanding of the effects of various factors upon the different sections of the brain? Yes.

Should the athlete himself have anything to do with this? NO!

The athlete is the specimen that is being studied. If the scientists wish to translate HIS art into THEIR science let them do so. Let them understand. Let them watch him and analyze him and dissect his movements.

FROM AFAR!

Let them keep their journals to themselves. Let them cover their computer screens. Let them keep their raw data locked inside their cluttered offices.

The only science that the athlete needs is his own idiosyncratic, personal, sloppy, patchwork science that he has accumulated through decades of toil in his trade. That ridiculous and unscientific science that only he knows. And that only he needs to know.

The science of adjusting the bill of his hat before the shot. The science of loosening his index finger on the grip. The science of clearing his throat before he jumps. The science of slapping his stick three times on the ice before he takes the face off.

The science which comes from his liver rather than his brain. The science that is completely unscientific. The science that is not rehearsed. The science that can never be written about in journals. The science that does not correspond to reason.

The science that a scientist will never understand. But which the athlete can reproduce in spades.

While it may provide an element of benefit for the athlete to perform in front of a machine, he will eventually begin to adjust his game for the data rather than the field of play. He will eventually begin to react according to the numbers rather than to the complex but wholly familiar situation that confronts him on the field.

The science of the athlete is not the science of muscle or brain. His is the science of fingertips. His is the science of the taste on his tongue. His is the science of perceiving the slight breeze coming off the Irish Sea. The one that instruments cannot measure. The one that only skin can feel.

His science is not the science of analysis. It is the science of FEELING. The science of KNOWING. Not in the contours of his brain. But within the chambers of his heart.

This is what must be fostered. This is what I emphasize with players.

For this is the type of science that no MRI can capture. And no electrode can detect.

This is the science of the athlete. And its magic lies in its being unscientific.

Thank you very much for your help, Sebastien. Is a similar device as accelerometers we have. I must read methodology to do it.

Thanks

Dear Raul,

When I said device I meant a smartphone or other mobile technology which identify their orientation through the use of an accelerator, a small device made up of axis-based motion sensing :). Que tengas mucho exito!

What about videoing them and using GPS to evaluate distance covered?

GPS or video tracking system = OUTDOOR

LPS or video tracking system = INDOOR

IMU = not useful to get the total distance during the match

The best and the easiest solution are using GPSport system. But it is necessary to have the expensive equipment. More complicated is the realization with video cameras. If you want to inspire with it look to this article:

HANK, M., MALY, T., ZAHALKA, F., DRAGIJSKY, M., BUJNOVSKY, D., Evaluation of the horizontal movement dinstance of elite female beach volleyball players during an official match, International Journal of Performance Analyisis in Sport, 2016, 16, 1087-1101

Thanks' everybody for your contributions.

At the ed, it is probable we will test with 3 axis accelerometer with gyroscop.

Keep in contact and thaks again

Raúl

Hi,

The main problem is your budget; according to it you can decide several solutions. The idea with the 3D accelerometers is fine. The sensors like GPSport are possible to wear during the match and we have very good experiences with using in soccer, volleyball and beach volleyball. The 3D video analysis is more complicated, work-intensive but it is very graphical when you can see the real picture and 3D data.

Feantisek

I would agree with Feantisek.

Dianne

I want to thank you everybody.

As I wrote before and some of you recommended me, accelerometre (IMU) will be the device used.

I will share with you the results when we have.

Good research

Hi Raul, the badminton field is well defined, with lines and visual limits. You could have a visual sticker on internal and external part of the two shoes of the player. Two cameras watching the player from the left resp. from the right will track the movement. Then you can estimate precisely the position and the speed of each foot. You get the trajectory. You can also tag the racket and track its movement. 

Picture processing is powerful...