Torque applications
Download
1 / 13

Torque Applications - PowerPoint PPT Presentation


  • 206 Views
  • Updated On :

Torque Applications. 1. Sprinting 2. Lower Back 3. Pushups 4. Weight lifting 5. Stability 6. Force Couple. Torque Applications. 1. Sprinting. Hip, knee flexion Swing phase Reduce moment arm. Torque Applications. 1. Sprinting Extreme flexion of the hip and knee

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Torque Applications' - Renfred


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Torque applications l.jpg
Torque Applications

  • 1. Sprinting

  • 2. Lower Back

  • 3. Pushups

  • 4. Weight lifting

  • 5. Stability

  • 6. Force Couple


Torque applications2 l.jpg
Torque Applications

  • 1. Sprinting

Hip, knee flexion

Swing phase

Reduce moment arm


Torque applications3 l.jpg
Torque Applications

  • 1. Sprinting

    • Extreme flexion of the hip and knee

      • Reduce moment arm/moment of inertia

        • T = F • dMA

        • T = I • a

          • Where I = m • r2

      • Increase pendulum frequency

        • f µ √(1/L)

          • Where: L = distance from center of mass to axis of rotation


Torque applications4 l.jpg
Torque Applications

2. Lower back


Torque applications5 l.jpg
Torque Applications

  • 3. Pushups - 2nd class lever

  • David is performing a pushup. He has a mass of 70 kg and is 175 cm tall. The top (superior) surface of his head is located 19 cm above (superior) to the shoulders. The center of gravity of his body is located at 53% of his height (starting at the inferior end). How much force do the arms have to produce at the shoulders to start a pushup for the ‘down’ position? Ignore the mass of the arms (8.5 kg).

  • Given: mDavid = 70 kg marms = 8.5 kg

    • Ht = 175 cm dCG = 53% Ht

    • D(head + neck) = 19 cm

  • Find: Farms Diagram

  • Farms

    dbody-arms

    19 cm

    Tarms

    0.53 • Ht

    aTm

    Tbody

    F(David-arms)


    Torque applications pushups l.jpg
    Torque Applications - Pushups

    • Formula: T = F • d

    • assume that in ‘down” position body is horizontal

    • F(body-arms) = (70-8.5 kg) (9.81 m/sec2) = 603.3 N

    • dCG = 0.53 • 175 cm = 92.75 cm D(HT-H+N) = 175 - 19 cm = 156 cm

    • Solution: Tarms > Tbody

    • Farms • D(HT-H+N) > F(body-arms) • dCG

      Farms > F(body-arms) • dCG / D(HT-H+N)

    • Farms > (603.3 N • 92.75 cm) / (156 cm)

    • Farms > 358.7 N or 52.2% of body weight

    Farms

    dbody-SH

    19 cm

    Tarms

    0.53 • Ht

    aTm

    Tbody

    F(David-arms)


    Torque applications7 l.jpg
    Torque Applications

    • Weight lifting

      No change in moment arm


    Torque applications8 l.jpg
    Torque Applications

    4. Weight lifting

    Moment arm changes as cam rotates


    Torque applications9 l.jpg
    Torque Applications

    Nautilus

    4. Weight lifting

    Free weight


    Torque applications10 l.jpg
    Torque Applications

    • 5. Stability

      • Wider base means greater moment of inertia and resistance to torque (ex. falling over)

    F


    Torque applications11 l.jpg
    Torque Applications

    • 5. Stability

      • More narrow base means smaller moment of inertia and less resistance to torque (ex. falling over)

    F


    Torque applications12 l.jpg
    Torque Applications

    • 6. Force Couple

    • A special case of parallel forces where two forces of equal magnitude are acting in opposite directions but at a distance from each other and on either side of the center of mass or axis of rotation. The result is no linear displacement or deformation, but increased potential for torque.

      • Tfc = F • Dfc

      • where D is the distance between the forces

      • Ex. Spin move in dancing

      • both hand pivoting on a golf club handle

    Dfc


    Torque applications13 l.jpg
    Torque Applications

    • 6. Force Couple - shoulder abduction

    supraspinatus

    Dfc


    ad