BWF biomechanics study presentation of the smash

Discussion in 'Techniques / Training' started by Tactim, Sep 8, 2017.

  1. Tactim

    Tactim Regular Member

    Joined:
    Sep 18, 2010
    Messages:
    924
    Likes Received:
    68
    Occupation:
    Nurse
    Location:
    Nor Cal



    Thought people would like to watch this one as there are very few studies done on the biomechanics of badminton technique.

    They only control for a few factors going into a smash but it's to keep it simple for the study. Interesting the smaller angle for the elbow (more bent elbow), produced a faster smash. We know that a straight arm definitely isn't the way to go, but bending your elbow even more during the swing and impact allows more pronation, therefore more power. He didn't study the optimal elbow angle but that will be studied later.

    We know most of what he's presented here from our own observations of pros and being coached, but having scientific data back up the currently best technique is always important and beneficial as it adds weight behind the modern technique.

    Anyhow, guess who was in the comment section being a smartass? Your very own Jazz Lopez!
     
    Barkov Maxim, gionna, Mazin and 9 others like this.
  2. pcll99

    pcll99 Regular Member

    Joined:
    Nov 19, 2009
    Messages:
    8,732
    Likes Received:
    630
    Occupation:
    Cylon
    Location:
    N/A
    sticky!!!
     
  3. swsh

    swsh Regular Member

    Joined:
    Mar 1, 2017
    Messages:
    2,038
    Likes Received:
    610
    Occupation:
    Student
    Location:
    Earth
    Lovely presentation. Enjoyed watching it and finished without a pause.
     
  4. visor

    visor Regular Member

    Joined:
    Dec 7, 2009
    Messages:
    16,401
    Likes Received:
    2,001
    Location:
    Vancouver, BC
    Tks @Ch1k0 for pointing me this video...
    I haven't had a chance to watch completely, will do that after work.
     
    #4 visor, Sep 8, 2017
    Last edited: Sep 8, 2017
    swsh likes this.
  5. rbynck

    rbynck Regular Member

    Joined:
    Feb 11, 2015
    Messages:
    201
    Likes Received:
    42
    Location:
    Denmark
    Really cool presentation!
    A tv-show in Denmark called "SportsLab" tried to do the same with Mads Pieler Kolding as test-subject and found out that most of the created energy came from the leg and abdominal muscles. They also took a closer look at the speed of the racket head, shuttle speed and energy created.
    It is fun to see that there are so many factors that play a part in how "hard" you can smash. And also nice to get an insight into the body movements, while the Danish show focused on the racket :)
    http s://imgur.com/a/Olxkv
     
  6. visor

    visor Regular Member

    Joined:
    Dec 7, 2009
    Messages:
    16,401
    Likes Received:
    2,001
    Location:
    Vancouver, BC
    Cool in a way, using similar method of bullet time 3D space recording a la Matrix.

    However, I think we can already know and analyze the shape of the smash motion with all the various super slow mo replay videos of the pros on YouTube.

    But I can see that what he's done is to put some measurable quantity numbers to see which matches with the fastest most effective smash. However again, there are certain qualifiers that can't be measured but only observed, eg. in the cricket study: lagging arm for best whipping/throwing action, and straightened leading leg for fastest throw.

    One other observation: I was rather not surprised that the pros' contact point is higher than the varsity players, but still surprised that the pros' contact point is not even higher (3 inches or so from the top) than I observe from slow mo replays.

    Sent from my P027 using Tapatalk
     
    #6 visor, Sep 8, 2017
    Last edited: Sep 8, 2017
    lotusknight likes this.
  7. DarkHiatus

    DarkHiatus Regular Member

    Joined:
    Oct 11, 2015
    Messages:
    1,207
    Likes Received:
    778
    Location:
    Manchester
    Is anyone surprised about the sweet spot?

    I have always been led to believe the sweet spot was about 1-2 inches above the geometrical centre of the racquet head! That's at least where the most fraying/string breakages occur?
     
    dave010 likes this.
  8. DuckFeet

    DuckFeet Regular Member

    Joined:
    Feb 22, 2012
    Messages:
    2,033
    Likes Received:
    320
    Occupation:
    Computer rebooter
    Location:
    Swindon
    Seconded. They didn't seem to be going all out, considering they were trying to measure top speed. Could just be that the video sample of Chris was his warm-up

    Sent from my SM-J510FN using Tapatalk
     
    lotusknight likes this.
  9. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    298
    Location:
    Surrey, UK
    Excellent presentation.

    I was not surprised about the contact point. I think people massively overstate the idea of a contact point that is (much) above the centre of the racket -- especially when players are using high tensions, as there will be a dramatic increase in stringbed stiffness for a significantly off-centre hit (and a greater chance of popping the strings).

    (I do agree that it seems to be slightly higher than centre, but not much.)

    More string breakages will occur when you hit off-centre, and strings will fray most wherever you hit the most (with power).

    The position of your string wear is a good indication of where your clears and smashes are getting hit. Ideally you have a very small area of wear near the centre. ;)

    The position of a string break can indicate whether it busted from an off-centre hit, or even a worn-out grommet (i.e. equal length each side of the grommet).
     
    #9 Gollum, Sep 12, 2017
    Last edited: Sep 12, 2017
  10. DarkHiatus

    DarkHiatus Regular Member

    Joined:
    Oct 11, 2015
    Messages:
    1,207
    Likes Received:
    778
    Location:
    Manchester
    I'll clarify between string wear and breakage:

    I break my strings most often in the area of highest wear (I inspect my grommets before restrings so side breakages are rare).

    My area of highest wear, and on many of my clients is 2 inches above the geometrical centre.

    The pros appear to contact the shuttle much nearer the geometrical centre. Does this mean the majority of amateurs are contacting the shuttle too high on the racquet face? (Which is especially surprising since most amateurs contact the shuttle low in the air)

    Unfortunately, pros will never let a string get that worn before restringing, so I don't know how accurate the camerawork is...but I imagine it is pretty well calibrated.
     
  11. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    298
    Location:
    Surrey, UK
    I can't know for sure, because I don't have good enough data. But that is a pet theory of mine. Everything I've seen suggests that pros hit consistently closer to the centre than amateurs.

    For some reason I feel it's very unnatural to hit low on the strings, and I never see anyone do it. I'm not sure why.

    I once strung a racket in an X shape with just a few strings in the centre, so that you basically had to hit right in the centre or the shot would (a) go right through the gaps or (b) have no control at all, due to the lack of stringbed support. Surprisingly I was able to hit okay with it maybe 50 -- 75% of the time, but my coach (ex pro) hit every single shot perfectly. It's slightly humbling
     
  12. DarkHiatus

    DarkHiatus Regular Member

    Joined:
    Oct 11, 2015
    Messages:
    1,207
    Likes Received:
    778
    Location:
    Manchester
    Genius idea. Is this a practice you would recommend? I have a spare racquet or two around, I am thinking 4/5 strings wide? Or is that too difficult?
     
  13. eiji

    eiji Regular Member

    Joined:
    Jun 26, 2017
    Messages:
    212
    Likes Received:
    95
    Location:
    Singapore
    I like the final question and his comments, that most non-elite players play rackets that are too stiff for them.

    I believe with more data analysis, we might be able to do a badminton racket fitting similar to how golfers get fitted for their golf clubs with the right loft and shafts to generate optimum distance and launch angles for their swings. We all swing differently, it would be great to have an understanding of what time of flex, head shape, string tension would suit us best to play to our desired game type(attacking, defensive, control, etc)
     
    visor likes this.
  14. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    298
    Location:
    Surrey, UK
    I've never tried actually using it in coaching, although it might work. I think it's mostly a bit of fun, and perhaps useful for finding out how accurate you really are.

    I believe I used 4 strings crossing each other, so you end up with a (45 degree rotated) grid of 9 squares in the middle and pretty much have to hit the centre square or you're stuffed. :D

    You need a racket you're prepared to break (although most likely you won't), and somewhat tough strings, and fairly low tension.
     
  15. eiji

    eiji Regular Member

    Joined:
    Jun 26, 2017
    Messages:
    212
    Likes Received:
    95
    Location:
    Singapore
    You can also get those head covers and cut a hole in the middle around the sweet spot, there will be some air resistance on the racket, which you can fit by cutting small holes on it to allow air to flow through, but generally shots off the sweet spot will be an obvious thud vs the feeling of hitting the stringbed
     
  16. DarkHiatus

    DarkHiatus Regular Member

    Joined:
    Oct 11, 2015
    Messages:
    1,207
    Likes Received:
    778
    Location:
    Manchester
    I'll give it a go with a racquet at 18lbs. Any reason why you opted for X against a + pattern?
     
  17. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    298
    Location:
    Surrey, UK
    Probably the X was overkill, but my thinking was that it punishes "too high" hits more. In reality, a + should do this fine too, due to the complete lack of support from adjacent strings.
     
  18. R20190

    R20190 Regular Member

    Joined:
    Jun 11, 2004
    Messages:
    2,458
    Likes Received:
    414
    Occupation:
    Chartered Civil Engineer
    Location:
    London, UK
    I was thinking of your thread on the contact point when I watched that presentation. It seems that pros (or at least the pros they studied) do tend to hit near the centre of the string bed...
     
    visor likes this.
  19. nbonkowsky

    nbonkowsky Regular Member

    Joined:
    Mar 19, 2011
    Messages:
    163
    Likes Received:
    34
    Occupation:
    Athlete/Coach
    Location:
    Calgary AB Canada / Trinidad and Tobago
    There was a continuation of this study happening at the world championships this year and I had the opportunity to participate in it. Still waiting for my personal package of the result and model, etc. Definitely not the fastest smash at just 311kpm/194mph but at the upper end of those who did it at worlds.

    Was a cool process, but some of the reflective ball didn't stick as well and flew off when smashing. Overall a cool experience and happy to participate in it. Can't wait till they publish that study and maybe use it in my own training.

    21868466_10159433895065327_1203282808_o.jpg 21875503_10159433895185327_2071110176_o.jpg 21908317_10159433894990327_888045404_o.jpg 21886882_10159433894975327_890866595_o.jpg
     
    Dave Dien, Cheung, It'sMeMeMe and 5 others like this.
  20. Mazin

    Mazin New Member

    Joined:
    Feb 7, 2016
    Messages:
    11
    Likes Received:
    1
    Location:
    India
    "Interesting the smaller angle for the elbow (more bent elbow), produced a faster smash"Pls explain I c
     

Share This Page