Week3

Week3

Deformation of tissue

Loading on tissue

  • Axial

    • compression
    • tension
  • Shear

    • also along one axis, but in opposite directions (and missaligned)
  • Multi-axial

    • bening
    • torsion why?

slipped femoral capital epiphisys examples

ACL is less taut with knee flexion

Stress: force per unit area. Area is measured over plane normal to force vector.

Strain: change in dimension/shape.

how does young’s modulus differ from slope?

Comminuted: Medicine (of a fracture) producing multiple bone splinters.

Why can tissue withstand more strain than it’s maximum load before fracture?

Friday

sign up for group projects (groups of 3 or 4)

Load - deformation curve vs. stress - strain curve (basically the same for our purposes)

“stiffness of tissue (basically its spring constant) produces linear stress-strain curve in elastic region.

Acute inflammatory process will likely begin around plastic deformation point of tissue.

Strain curve shows muscle stretching more than ligament (how does this stack up agains Seifert’s claim that tendon stretches more than muscle?)

why is rate of load in bone measured in MegaPascal’s per second

resilience: Ability to endure loads within elastic limits

toughness: area under entire curve.

  • stiffness
  • strength
  • elasticity
  • ductility
  • brittleness
  • maleability
  • toughness
  • resilience