Biomechanics Flashcards
What are the three types of deformations?
- Tension: Stretching a material along its length
- Movement: Deformation caused by mechanical motion
- Pressure: Deformation due to compressive forces acting uniformly on a surface
Define relative deformation.
Measures the degree of deformation, proportional to the applied force and inversely proportional to the cross-sectional area of the material
What is Young’s Modulus?
A mechanical property measuring a material’s stiffness under tension, defining how much strain a material undergoes under stress
What is the unit of Young’s Modulus?
Pascals (Pa) or Nm^-2
What characterizes Hookean materials?
- Obey Hooke’s Law: deformation is proportional to applied force
- Linearly elastic
What is the potential energy formula for Hookean materials?
U = 0.5kL^2, where k is the stiffness constant and L is deformation length
Provide an example of a Hookean material.
Steel
What characterizes non-Hookean materials?
Do not obey Hooke’s Law
Provide an example of a non-Hookean material.
Rubber
How does mechanical strain relate to deformation for small deformations?
Mechanical strain is proportional to relative deformation
What happens to the graph of mechanical strain beyond the elastic limit?
The graph deviates, showing non-linear behavior
What is viscous resistance?
Measures the non-ideal behavior of materials during deformation-relaxation cycles
What are the components of muscle deformation?
- Plasticity: Ability to maintain deformation after removing external force
- Elasticity: Ability to stretch and return to the original size
- Viscosity: Resistance to changes in shape under dynamic conditions
- Solidity Margin (Tension Bound): Flexibility of the muscle system under tension
What happens to free energy during reversible or irreversible deformation?
Free Energy decreases
How is chemical energy transformed during muscle contraction?
Directly transformed into mechanical energy without intermediate energy forms like heat or electricity
