Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 22

Thread: Barrel-Forearm Alignment

  1. #1
    Always learning... Eric F's Avatar
    Join Date
    May 2013
    Location
    SoCal
    Posts
    9,045
    Thanks
    5,748
    Thanked 7,057 Times in 3,619 Posts

    Default Barrel-Forearm Alignment

    I read something yesterday that was describing the alignment of the barrel and the lead forearm at contact.

    This isn't a detail I have heard discussed before. As I looked through a bunch of pro swings, this appears pretty typical (or close to it).




    Thoughts?

    Last edited by Eric F; 03-14-2019 at 12:44 PM.
    A TB parent's life...Drive. Write checks. Eat tacos.

  2. #2
    Clueless.. pattar's Avatar
    Join Date
    Jun 2016
    Posts
    1,759
    Thanks
    316
    Thanked 871 Times in 573 Posts

    Default

    Just a guess but this quote:

    "It was shown that the maximum speed of the rod results if
    the pendulum arm comes to a temporary stop at the instant
    when the rod and the arm are both vertical. In that case, all
    the initial potential energy of the system ends up as kinetic
    energy in the rod."

    from this paper:

    https://www.physics.usyd.edu.au/~cro...0DPendulum.pdf

    might have something to do with it. In the quote the rod is the bat and the forearm is the pendulum arm and
    "both vertical" here refers to when they are aligned.

    The forearm does not come to rest obviously but it does slow down right before contact if I remember correctly.
    Last edited by pattar; 03-14-2019 at 01:36 PM.

  3. The Following User Says Thank You to pattar For This Useful Post:

    Eric F (03-14-2019)

  4. #3
    Always learning... Eric F's Avatar
    Join Date
    May 2013
    Location
    SoCal
    Posts
    9,045
    Thanks
    5,748
    Thanked 7,057 Times in 3,619 Posts

    Default

    Quote Originally Posted by pattar View Post
    Just a guess but this quote:

    "It was shown that the maximum speed of the rod results if
    the pendulum arm comes to a temporary stop at the instant
    when the rod and the arm are both vertical. In that case, all
    the initial potential energy of the system ends up as kinetic
    energy in the rod."

    from this paper:

    https://www.physics.usyd.edu.au/~cro...0DPendulum.pdf

    might have something to do with it. In the quote the rod is the bat and the forearm is the pendulum arm and
    "both vertical" here refers to when they are aligned.

    The forearm does not come to rest obviously but it does slow down right before contact if I remember correctly.
    Science!...
    A TB parent's life...Drive. Write checks. Eat tacos.

  5. #4
    Certified softball maniac Shawn's Avatar
    Join Date
    Jan 2009
    Location
    Pacific NW
    Posts
    1,820
    Thanks
    345
    Thanked 418 Times in 339 Posts

    Default

    Is it the lead arm and bat are aligned, that the bat is an extension of the lead arm?
    "It is hard to fill a cup that is already full"

  6. #5
    Certified softball maniac Shawn's Avatar
    Join Date
    Jan 2009
    Location
    Pacific NW
    Posts
    1,820
    Thanks
    345
    Thanked 418 Times in 339 Posts

    Default

    Quote Originally Posted by pattar View Post
    Just a guess but this quote:

    "It was shown that the maximum speed of the rod results if
    the pendulum arm comes to a temporary stop at the instant
    when the rod and the arm are both vertical. In that case, all
    the initial potential energy of the system ends up as kinetic
    energy in the rod."

    from this paper:

    https://www.physics.usyd.edu.au/~cro...0DPendulum.pdf

    might have something to do with it. In the quote the rod is the bat and the forearm is the pendulum arm and
    "both vertical" here refers to when they are aligned.

    The forearm does not come to rest obviously but it does slow down right before contact if I remember correctly.
    I had a science question for you, although I can't remember what the heck it was now.
    "It is hard to fill a cup that is already full"

  7. #6
    Always learning... Eric F's Avatar
    Join Date
    May 2013
    Location
    SoCal
    Posts
    9,045
    Thanks
    5,748
    Thanked 7,057 Times in 3,619 Posts

    Default

    Quote Originally Posted by Shawn View Post
    Is it the lead arm and bat are aligned, that the bat is an extension of the lead arm?
    As I'm understanding this, the bat reaching a point of being in alignment with the lead forearm at the moment of contact is the goal for maximum bat speed (although just before impact is probably good enough in the real world). Extrapolating from that...The upper arm, forearm, and bat all being in line would be ideal, assuming the parts all reach alignment at/before impact. However, certain pitch locations would be limiting to the ability to achieve 3-part alignment.

    (The above is an assumption from someone with a mediocre understanding of physics.)
    A TB parent's life...Drive. Write checks. Eat tacos.

  8. #7
    Dad, Coach, Chauffeur SB45's Avatar
    Join Date
    Sep 2016
    Location
    Western NY
    Posts
    125
    Thanks
    50
    Thanked 86 Times in 59 Posts

    Default

    In my head...if the bat lags behind as it should, it doesn't catch up to that alignment with the lead forearm until contact...accelerating just at the right time. If the hands start to early, and there is no lag..the bat seems to be aligned with the forearm too early and doesn't have that same acceleration at the point of contact.

  9. #8
    Certified softball maniac Shawn's Avatar
    Join Date
    Jan 2009
    Location
    Pacific NW
    Posts
    1,820
    Thanks
    345
    Thanked 418 Times in 339 Posts

    Default

    Quote Originally Posted by Eric F View Post
    As I'm understanding this, the bat reaching a point of being in alignment with the lead forearm at the moment of contact is the goal for maximum bat speed (although just before impact is probably good enough in the real world). Extrapolating from that...The upper arm, forearm, and bat all being in line would be ideal, assuming the parts all reach alignment at/before impact. However, certain pitch locations would be limiting to the ability to achieve 3-part alignment.

    (The above is an assumption from someone with a mediocre understanding of physics.)
    I think I gotcha. The alignment is different as usually shown by people of a contact position. What is usually shown is the bat and lead arm aren't a extension of each other. The lead arm is extending out front and the bat is at 90 degrees. It's a poor visual compared to the pics you posted.
    "It is hard to fill a cup that is already full"

  10. #9
    Always learning... Eric F's Avatar
    Join Date
    May 2013
    Location
    SoCal
    Posts
    9,045
    Thanks
    5,748
    Thanked 7,057 Times in 3,619 Posts

    Default

    Quote Originally Posted by SB45 View Post
    In my head...if the bat lags behind as it should, it doesn't catch up to that alignment with the lead forearm until contact...accelerating just at the right time. If the hands start to early, and there is no lag..the bat seems to be aligned with the forearm too early and doesn't have that same acceleration at the point of contact.
    The problem is that the typical "bat-lag" approach includes pushing the hands forward, which moves the center of rotation for the barrel, and may make it more difficult to achieve bat-forearm alignment. Early barrel speed and a deep turn leads to the position you see Khris Davis in (bottom right in the pic above). You can't get there if you lag and push.

    I'm not sure how much velocity penalty there is for getting to alignment early and carrying that velocity through contact, but I suspect that's a better trade-off than being late. One thing I also see with hitters (including my DD) who aren't getting to alignment before contact, is that the hands often are moving left around the body and pulling the barrel laterally across the ball during contact, which costs power.
    A TB parent's life...Drive. Write checks. Eat tacos.

  11. #10
    Always learning... Eric F's Avatar
    Join Date
    May 2013
    Location
    SoCal
    Posts
    9,045
    Thanks
    5,748
    Thanked 7,057 Times in 3,619 Posts

    Default

    This is the Tweet that got me thinking about this topic...https://twitter.com/LineDrivePro/sta...41596362481664

    A TB parent's life...Drive. Write checks. Eat tacos.

Page 1 of 3 1 2 3 LastLast

Posting Permissions

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