Biomechanics Flashcards
What is biomechanics?
The science examining internal/external forces acting on the human body, and the effects produced by these forces.
Where is biomechanics used?. (There are 6 different examples)
Health and Phys. Ed. Sports medicine. Physical therapy Kinesiology Biomechanical engineering Zoology
Compare quantitative and qualitative studies.
Quantitative: Numbers, data that can be measured.
Qualitative: Descriptions, observed data.
What can biomechanists can provide coaches and instructors with? (4 points)
- Knowledge on how a skill is done.
- A basis for comparison of techniques.
- Better teaching and coaching techniques.
- Improved error detection and correction.
What does kinematics describe?
Spatial and timing characteristics of the human body and its segments.
What 4 questions does kinematics answer about a motion?
How long, fast, far, consistent.
List the 7 kinematic variables.
Time Displacement Velocity Acceleration Angular displacement Angular velocity Angular acceleration.
Would variable describes the velocity of a baseball pitcher’s arm?
Angular velocity.
Compare displacement and velocity.
Displacement: distance & direction.
Velocity: speed (magnitude) and direction.
What does kinetics focus on?
Various forces that cause a movement. Can be internal or external.
Generally, internal forces cause _______ movements, and external forces affect ______ movements.
individual body, total body
Describe the particle model of analysis.
A dot represents the center of mass of an object.
Gravity is usually the only external force. (sometimes air resistance).
Object/body is called a projectile.
In what situation would you use a particle model for motion analysis.
When the object is airborne / in flight.
Describe the stick figure model.
Body is represented as a stick figure.
External forces are shown with vectors.
In what situation would you use a stick figure model?
When the athlete is in contact with the ground or an earth-bound object.
Gross motor skills that occur in two dimensions.
Not good at representing fine muscle movements.
What is a composite diagram?
A sequence of stick figures representing either the total body or portion thereof.
Describe the rigid segment model. When would this model be used?
Body parts are irregularly shaped 3D volumes. Used for sophisticated 3D analysis.
What are the 3 steps of analysis?
- Identify system to be studied (isolate)
- Identify frame of reference.
- Identify type of motion.
What are the three types of motion?
Linear, angular, general.
Describe linear motion. Give an example.
When all parts of the body move in the same distance and direction at the same time. Translation. (eg toboggan run)
Compare the two types of linear motion (rectilinear and curvilinear).
Rectilinear: movement follows a straight line.
Curvilinear: movement follows a curved line.
Describe angular motion.
Body moves on a circular path and in the same direction. Rotation. (eg gymnast swinging on a bar)
Describe general motion.
A combination of linear and angular. Most common in everyday activities.
What is moment of force, or torque?
When a force causes angular motion. (eg. opening a door)
What is a fulcrum?
The axis of rotation (ex. the centre of a teetor totter)
What is a moment arm?
The shortest distance from the axis of rotation to the line of action.
What is the eqn for calculating moment of force?
Moment of force = Moment arm x Force
What is a lever?
A mechanical device that augments the amount of work done by an applied force.
Can you identify the three classes of levers?
http://leo.koppel.ca/backhoe/levers.png
Compare scalar and vector quantities.
Scalar: magnitude only (speed is 100km/h)
Vector: magnitude and direction (velocity is 100km/h north)
