torque/levers

• Torque (or moment): Rotary effect of a force about an axis of rotation

  • T= F x d. (of moment arm from axis)
  • Moment arm of a force= perpendicular distance from the force’s line of action to the axis of rotation.
• levers:

  First=

  ·      A is between the F/R (most versatile).

  ·      Balance forces, ROM, move a force.

  ·      Example= triceps extending overhead

  Second:

  ·      R between F/A

  ·      Have a force advantage.

  ·      Example= calf raise, push up, eccentric bicep curl.

  Third:

  ·      F between A/R.

  ·      Most common lever in the body.

  ·      Provides speed/ROM advantage for light loads.
• Mechanical advantage:

  ·      Mechanical advantage= force arm/resistive arm.

  ·      FA> RA= MA> 1 larger force can be balanced (FORCE ADV)

  ·      RA>FA= MA< 1 move resistance through large range of motion (ROM)
• Anatomical Levers

  ·      Rotary component always acts perpendicular to the bone (Provides force to rotate)

  ·      Parallel component= stabilizing component=dislocating component