Lecture 3 Flashcards
Calibrating movements to achieve a ____ in a _____ requires some (____ or ____) knowledge of _____ _____.
- task
- environment
- implicit or explicit
- physical mechanics
During development, change in ____:_____ constraints and the interaction with things like ______ are important limiters of motor patterns.
- individual: structural
- gravity
Newton’s First law:
- an object at rest stays at rest and an object in motion stays in motion until acted upon by a force
- inertia is resistance to motion related to mass
- momentum is the product of mass and velocity
Newton’s first law states that we must exert force to:
- move objects
- move ourselves
Newton’s first law states that more inertia means that:
- it is harder to move
- more force application is required
To move an object farther or faster, you must:
- increase force
- increase distance over which force is applied
What are 2 ways we can add distance to improve a kick?
- increase step length (linear distance)
- increase ROM (rotational distance)
Newton’s second law:
- object’s force is related to mass and acceleration (F = ma)
- object’s acceleration is related to force applied and inversely related to mass (a = F/m)
Newton’s third law:
to every action there is an equal and opposite reaction
How is Newton’s third law used?
oppositional movements and directional force
Give examples of oppositional movements.
- oppositional arms and legs movement in running
- running: push down on floor and floor pushes back up
What does exerting force in primary movement plane mean?
- use force in the plane of motion which you want to move yourself or an object
- avoid rotational movements that reduce force in the desired plane
How can we increase velocity in rotating limbs and projected objects?
- increase rotational velocity (swing it faster)
- increase relative length (fully extend it at release or contact)
Why not keep the limb extended throughout a rotational motion?
leg would have too much rotational inertia
Stability:
ability to resist movement
