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What is the definition of biomechanics?
Application of mechanical principals in the study of living organisms.
What is the difference between a qualitative and quantitative analysis?
qualitative --> non-numeric description or evaluation of movement based on observation
quantitative --> numeric description or evaluation of movement based on data collected during performance
what is force?
effect that one body has on another
push or pull applied to an object
a requirement to change acceleration of an object
What are some examples of internal and external forces that act on the human body?
internal --> muscle tension, muscle force, ligament tension, bone compression
external -->friction, gravity, joint reaction force
What is a vector and what are some examples of vectors?
Vector --> a quantity that is defined by its size/magnitude and direction
Examples --> force, moment, velocity, and acceleration
Why do you resolve a vector into components?
You resolve a vector into components by determining a single force vector from two or more forces vectors by vector addition
What is the process to resolve a vector?
Check if the vectors are colinear (tip-to-tail) or concurrent vectors (tip-to-tail method composition)
Composition vectors with the same directions require adding their magnitudes
Composition vectors with opposite directions require subtracting their magnitudes
When can friction be beneficial?
Friction is beneficial when the coefficient gets to be greater than the surface of contact
How can you increase or decrease the force of friction?
Increase the force of friction by normal reaction force and coefficient of friction
Decrease the force of friction by lower coefficient of friction and lower reaction normal force
What is the difference between displacement and distance?
Displacement --> straight line distance in a specific direction from initial to final position
Distance --> length of path followed by object from initial to final position
What is angular motion? What are some examples?
Angular motion --> rotation (how limbs rotate) or fixed point/rotation around a fixed point
Examples --> diver (spinning), ball spinning in the air, join motion, gymnast swinging around high bar
What can impact the horizontal displacement of a projectile?
Maximize velocity horizontally
Increase initial release height
What are Newton’s 3 Laws?
law of inertia
law of acceleration
law of reaction
What is Impulse and how does it relate to Momentum? What are some examples of how impulse can be manipulated in a collision?
Impulse --> when force is applied to a body, the resulting motion is dependent upon both the magnitude and duration of force
Momentum changes rely on impulse (magnitude of external force and length of time over which external force acts)
Example: using airbags helps reduce the severity of many automobile collisions
What is the radius of rotation?
Ratio of the arc length (r) of a circle to the radius length
What is radial Acceleration?
Directed toward the center, along the curved path (represents change in direction)
Linear speed of an object traveling a curved path remains constant
Direction of object traveling a curved path is constantly changing
Also perpendicular to path of motion (center seeking)
What is the relationship between angular displacement and linear displacement?
Angular displacement --> at an angle towards center
Linear displacement --> straight follows a pathway
Relationship --> analogous to linear distance
↑ radius of rotation = ↑ linear displacement
What are the 3 muscle actions and how are they different from each other?
Concentric --> shortening of fibers to cause joint movement
How is torque calculated?
Find perpendicular distance (moment arm) / T = F∙d⊥
Find the perpendicular component of the force (lever arm) / T = F⊥∙d
What is the impact of the angle at which a muscle force is applied within a joint torque?
Changes the amount of rotary and non-rotary forces
How does the angle influence non-rotary forces?
Compressive forces compare to distraction forces
How do non-rotary forces influence the joint?
Compressive forces when the non-rotary is going into the joint dislocation force with a non-rotary force is going away from the point
What is a mechanical advantage?
Ratio of the lever arm of the motive force to the lever arm of the resistive force for a given lever
Mechanical advantage = Lever arm motive/ lever arm resistive
Which type of lever(s) have a mechanical advantage?
Lever two has a mechanical advantage (always)
First lever --> depends
Third lever --> never mechanical advantage
Describe tension, shear, and compression. Use diagrams to aid in your explanation.
Tension --> pulling or stretching force directed axially through a body
Shear --> force-directed parallel to a surface
Compression --> pressing or squeezing force directed axially through a body