Principles of Motion and Stability 2 Flashcards
define force absorption
the process of decreasing the force of an impact between 2 objects/people
*important in injury reduction, reduce stress from impact
*body absorbs force- transfers to muscles, equal and opposite force of contraction cancels the force
list some sport examples talked about in class that require force absorption
- gymnastics landing
- recieving a pass/stopping ball
- freestyle skiing
- baseball - catching ball
- wrestling
- talking hit in boxing
claire’s examples: - figure skaters landing
- baseball - ball catch or sliding into base
- weightlifting
- volleyball, volley
what 2 types of collision are under force absorption?
elastic and inelastic collisions
describe elastic collisions
a collision where there is no loss of kinetic energy
ex. newton’s cradle
describe inelastic collisions
part of the kinetic energy is changed to some other form of energy in the collision
ex. car crash - get thermal energy out, deformation
*energy is lost/transferred
define linear velocity
radius x rotational velocity
how are rotational velocity and linear velocity related in human movement?
rot velocity of a limb causes llinear velocity of an object once released
*the faster we can rotate, the faster we can send the object
linear velocity = how fast you can go
rot vel = how fast you are swinging your arm
radius = shoulder to hand
how can we throw a ball faster based on what we know about limb rotation and projected objects?
- more rotational velocity by changing technique
- longer arm at release
- windup (smaller initial limb length takes less energy to initiate movement - law of inertia)
- use more complete range of motion to increases benefits of the contractile properties of the recruited muscles
describe closed kinetic chain
movements are constrained at the distal end of the segment
ex. squatting, push ups
describe open kinetic chain
movements are unconstrained at the distal end of the segment
ex. kicking, bench press
list the examples of open kinetic chain movements from class
- kicking (legs can move freely)
- arm raises
- waving
- throwing
- cycling
list the examples of closed kinetic chain movements from class
- downward dog (pushing against floor which does not move +constrains)
- lunge (feet pushing into ground, restricts distal segments)
- running (applying force against earth to move)
define balance
the ability to maintain equilibrium
define stability
the strength to endure
- to develop forces that restore the original condition
people construct generalized motor programs by
exploring programming rules, and learning the ways that certain movements are related
describe schmidt’s theory of motor control
the relationship between the parameters and outomes are collected in “schemes” or “schema”
define recall schema
relates outcomes to parameters (ie. movement duration, force production)
define recognition schema
relates expected sensory consequences of a movement to the movement’s outcome
describe the graph on schmidt’s generalized motor program theory
x axis- movement outcome
y axis -parameter (movement duration/force)
- parameters are features of a movement
- by scaling different parameters, this will produce different variations of the same movement (ex. writing really small and big, throwing close and far)
- helps understand how changing parameters affects movement outcome
- get best fitting straight line
