221920 Bullies, 3955 online  
  • Register
Our Sponsors:

Results 1 to 10 of 79
Page 1 of 8 1 2345 ... LastLast
Sponsored Links Spacer Image
  1. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/20/2013 12:41pm


     Style: Hapkido

    --
    Hell yeah! Hell no!

    Levers in martial arts

    Hey guys. I have another blog post I though might be of interest here.

    It covers levers mostly, and discusses the two ways you can use them:
    1) Trade in some distance in exchange for more force
    -or-
    2) Trade in some force in exchange for more distance (which gives more speed)

    I included a few examples from eskrima and grappling, but I'd really like to hear if you guys have some better examples of leverage at work.

    http://theamazingdoctorawesome.blogs...e-lunches.html
  2. ChenPengFi is online now
    ChenPengFi's Avatar

    Senior Member

    Join Date
    Aug 2005
    Location
    Hawai'i
    Posts
    3,262

    Posted On:
    9/20/2013 1:06pm

    Join us... or die
     Style: Hung Gar, Choy Lay Fut

    --
    Hell yeah! Hell no!
    Well, you have science words, levers, wedges (ie triangles) and _ng _un.

    Is there really anything to add?
  3. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/20/2013 1:37pm


     Style: Hapkido

    --
    Hell yeah! Hell no!
    Quote Originally Posted by ChenPengFi View Post
    Well, you have science words, levers, wedges (ie triangles) and _ng _un.

    Is there really anything to add?
    Ha. Yea, I had to sift through a lot of science words applied... let's say "over-ambitiously" when I put this together.
  4. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/21/2013 8:28am


     Style: Hapkido

    --
    Hell yeah! Hell no!
    I really would like some ideas for a few special examples, so I can sit down and work out the math, though. I was thinking about maybe knife or gun disarms, or something like that, where we can actually quantitatively compare the difference in force you need to apply using brute force vs letting the lever help you out.
  5. ChenPengFi is online now
    ChenPengFi's Avatar

    Senior Member

    Join Date
    Aug 2005
    Location
    Hawai'i
    Posts
    3,262

    Posted On:
    9/21/2013 11:27am

    Join us... or die
     Style: Hung Gar, Choy Lay Fut

    2
    Hell yeah! Hell no!
    The difference between cradling the neck and the back of the head is marked, during a clinch/plum/snap-down.

    A quick explanation of how extrapolation of the length works in regards to lever arms/fulcra would be nice; the maths for newbs...

    Kinetic energy vs force, since you brought up velocity, might deserve a nod.
  6. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/21/2013 1:14pm


     Style: Hapkido

    --
    Hell yeah! Hell no!
    Quote Originally Posted by ChenPengFi View Post
    The difference between cradling the neck and the back of the head is marked, during a clinch/plum/snap-down.

    A quick explanation of how extrapolation of the length works in regards to lever arms/fulcra would be nice; the maths for newbs...

    Kinetic energy vs force, since you brought up velocity, might deserve a nod.
    Oh man, that is a perfect example to dig into further. Simple in concept, you can test it yourself, the numbers are all measurable... Thank you.

    As for the kinetic energy vs force thing, I think that is probably the single most common mix-up you see. I made a whole blog post just for that distinction here:

    http://theamazingdoctorawesome.blogs...our-fists.html

    But here's the quick version: Force gives you a change in momentum. It lets you move things around, knock them over, push them back, etc. Energy is more related to your ability to do localized structural damage to something, like break bones, skin, cause bruises, etc.

    Usually, when this gets mixed up on tv shows like "fight science", you see them measure the force of impact, and then make some wild comparison to show the kind of structural damage it would do.

    A firmly tossed pillow has the same force of impact as a bullet to the head, FYI. It doesn't mean pillows are deadly.
  7. ChenPengFi is online now
    ChenPengFi's Avatar

    Senior Member

    Join Date
    Aug 2005
    Location
    Hawai'i
    Posts
    3,262

    Posted On:
    9/21/2013 1:30pm

    Join us... or die
     Style: Hung Gar, Choy Lay Fut

    --
    Hell yeah! Hell no!
    Ah, i missed that link earlier.


    This section:
    So the quick rule to levers in fighting is: grab the long end when you want to control your opponent, and grab the short end when you want to hurt him.

    has some problems as written.
    Controlling hips and posture/base are kind of at opposite ends of this.
  8. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/21/2013 1:31pm


     Style: Hapkido

    --
    Hell yeah! Hell no!
    Quote Originally Posted by ChenPengFi View Post
    The difference between cradling the neck and the back of the head is marked, during a clinch/plum/snap-down.

    A quick explanation of how extrapolation of the length works in regards to lever arms/fulcra would be nice; the maths for newbs...

    Kinetic energy vs force, since you brought up velocity, might deserve a nod.
    And here's a little more of the math on the levers:

    A lot of coverage on levers breaks them down into class 1, class 2, class 3, etc, all depending on where the fulcrum, load, and applied force are in relation to each other. I don't like that kind of treatment, because I think it distracts from what is really going on at the heart of it all:

    You are using a rigid arm rotating around a point to translate your movement from a linear system to a rotational one and then from that rotational system back to new linear system. Force times distance from rotation on the way in must be equal to force times distance on the way out, due to the conservation of energy. That statement is true no matter what kind of lever you have or what you are doing with it.

    So whatever you do to change the distance on the way out, the opposite happens to the force (double distance = 1/2 force, etc).

    Of course, we talk about force here because the math is just force times distance and that makes it easy. If we want to start talking about energy, it gets complicated very quickly and we have to start asking specific questions about specific examples.

    Does that help with the maths?
  9. ChenPengFi is online now
    ChenPengFi's Avatar

    Senior Member

    Join Date
    Aug 2005
    Location
    Hawai'i
    Posts
    3,262

    Posted On:
    9/21/2013 1:53pm

    Join us... or die
     Style: Hung Gar, Choy Lay Fut

    1
    Hell yeah! Hell no!
    Quote Originally Posted by Dr_Awesome View Post

    So whatever you do to change the distance on the way out, the opposite happens to the force (double distance = 1/2 force, etc).
    This is what i was getting at.
    it seems you are targeting a layperson audience so keeping it practical might be beneficial.
    Something like this (i would have preferred 100 and 10 kg, and 10 units of length...)


    and this:



    and this:


    can go a lot further than text.


    Of course, we talk about force here because the math is just force times distance and that makes it easy. If we want to start talking about energy, it gets complicated very quickly and we have to start asking specific questions about specific examples.
    My point exactly, and that criticism stands as it is.


    Does that help with the maths?
    Just giving feedback.
  10. Dr_Awesome is offline

    Registered Member

    Join Date
    May 2013
    Location
    Austin, Texas, United States
    Posts
    100

    Posted On:
    9/21/2013 3:13pm


     Style: Hapkido

    --
    Hell yeah! Hell no!
    Quote Originally Posted by ChenPengFi View Post
    This is what i was getting at.
    it seems you are targeting a layperson audience so keeping it practical might be beneficial.
    Something like this (i would have preferred 100 and 10 kg, and 10 units of length...)


    and this:



    and this:


    can go a lot further than text.




    My point exactly, and that criticism stands as it is.




    Just giving feedback.
    That feedback is very helpful. You're right, visualizing things makes it easier to understand quickly and easily (way more than text), and I should probably lean on stuff like that way more often than I do. Helping me with clarity is probably the best help I could ask for. Thank you.
Page 1 of 8 1 2345 ... LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Powered by vBulletin™© contact@vbulletin.com vBulletin Solutions, Inc. 2011 All rights reserved.