Biomechanics

Question 1

What are levers?

Answer 1

Rigid objects that rotate around a fixed point
- the bones in the skeleton form a lever system and muscles act on tendons to change the angles

Question 2

What determines how much a muscle can shorten?

Answer 2

The muscles length but mist can shorten to around 50% of their original length

Question 3

Why is a parallel formation of fibres beneficial for muscles?

Answer 3

Allows a greater range of motion (ROM) and less force is developed

Question 4

What does the tendon to muscle ration impact?

Answer 4

The force and range of motion potential within a muscle

Question 5

What are the two main determining factors of muscle power?

Answer 5

1. Cross-sectional area of muscle
2. Where fibres join tendons at an angle

Question 6

What are these examples of…..?
Heel strike
Stance
Toe off
Swing phase
Ground reaction force
ect ect.

Answer 6

Terms that define locomotion

Question 7

What are the definitions of biomechanics for…
… physics
… classical mechanics

Answer 7

Physics - Study of matter and its motion in space and time
Classical mechanics - how bodies (solids + fluids) or systems of bodies respond to external forces

Question 8

What does hysteresis mean?

Answer 8

Energy dissipation

Question 9

Which is reversible and which is irreversible for bones?
Plastic deformation
Elastic deformation

Answer 9

Plastic = irreversible
Elastic = reversible

Question 10

What are the four types of loads that can be applied onto a bone?

Answer 10

Tension - stretching (resisted by collagen)
Compression - occurs due to weight bearing and muscle contractions (resisted by mineral content)
Shear - N/A
Torsion - occurs when mass of body changes direction whilst the limb is weight bearing (struggles to resist)

Question 11

When bones bend micro currents occur, how do osteocytes respond to these?

Answer 11

Compression is a negatively charged current and causes bone to be laid down
Tension is a positively charged current and it removes bone