Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
|
End effector
|
Sits a tthe end of chain and accomplishes task. It controls what is essential to completing the task.
Ex. In reaching, hand is EE. In kicking soccer ball, toe is EE. In standing balance, COM is EE. |
|
|
Effector Systems
|
All the joints and muscles that help the end effector accomplish the task.
Ex. In reaching, the UE is ES. In kicking a soccer ball, LE is ES. In standing balance, the entire body is the ES. |
|
|
Special Purpose device
|
Device that performs the task
Ex. We are a "tooth brusher" when we are brushing our teeth before bed. |
|
|
Affordances for action
|
Possibilites for action serviced by the objects in the enviornment.
Ex. chair = sit on ability floor = stand on ability In Parkour and Stomp, the individuals see possibilties we don't see |
|
|
Nagi Model
|
a) pathophysiology: cellular level
Ex. ACL tear, spina bifida, Parkinson's, stroke b) Impairment: organ level Ex. Contracture, ROM, cardiac output, muscle weakness, poor timing, pain c) functional limitation: whole body Ex. walking, climbing, running, reaching, grasping d) disability: society Ex. ADL, psychosocial, catching a bus, job |
|
|
ICF model
|
a) Health condition: pathophysiology
b) Body functions and structures: impairment c) Activity: functional limitations d) Participation: disability As well as: environmental factors, personal factors |
|
|
Constraints/Dynamics Model
|
Control and coordination are properties of a dynamical system that is constructed in the context of 3 types of constraints
|
|
|
Constraints
|
Task
Organism Enviornment |
|
|
Dynamical System
|
System that moves according to an underlying set of forces
|
|
|
4 Problems
|
1) DOF freedom problem
2) Movement Form Selection problem 3) Contexted Condition Variability problem 4) Infinite Regress problem |
|
|
DOF problem
|
Each joint has an independent DOF. How do they work together to produce an overall movement pattern?
|
|
|
Movement form selection problem
|
How will I get from here to there? What type of movement pattern should I select? Why are some locomotion forms/patterns kept or preferred but not others?
|
|
|
Context Conditioned Varability Problem
|
Once you picked a movement for, how do you deal with the fact that the patterns of muscle EMG activity used to produce that form will never be exactly the same?
|
|
|
3 Sources of CCV
|
Anatomical
Mechanical Physiological |
|
|
CCV: Anatomical
|
Activation of a particular muscle will result in different torques (and therefore motions) of the limb.
Depends on the the relationship between the muscle's line of pull and joint's rotational axis Ex. Postural effect, Muscle identity effect |
|
|
Postural effect
|
The same muscle will have a different action.
Line of pull and moment arm change above and below the rotational axis. Ex. Pec Major can do adduction when the limb is near the side and does abduction when the limb is out to the side. |
|
|
Muscle Identity effect
|
Different muscles can perform the same action
Ex. adduction: Deltoid (slow) and Lats (fast) Which one to select? |
|
|
CCV: Mechanical
|
Activation of a particular muscle will result in different motions of the limb depending on:
other forces acting on the limb initial mechanical state of the limb (i.e initial velocity of limb) Ex. concentric, eccentric, isometric Also, mass x acceleration = force (sum of forces acting on the limb) |
|
|
CCV: Physiological
|
The amount of muscle activation is determined by the sum of all influence (excitatory and inhibitory) on the motoneuronal pool.
|
|
|
Infinite Regress problem
|
Who/what is responsible for creating coordinated movement patterns?
Homonuculus (executive controller)? But who controls the executive controller...etc...etc. |
|
|
Self organization
|
Control of regular movement pattern is distributed through the system
Behaviors emerge from constraits without strict top down executive control. That is, with min reliance on executive intervention. |
|
|
Coordinated structures
|
Ensembles of muscles and joints that are recruited temporarily in a function specific manner to perform a given task in a manner consisten with the current set of organismic and enviornmental constraints.
Turn body parts into special purpose devices. |
|
|
Hierachial Theory
|
"Top Down"
Higher centers inhibit and control lower level "primitive" center. |
|
|
Neurocentric Theories
|
Neural processes account for everything. Movement patterns that are observed or ones that aren't observed (disappear/vanish).
Ex. Disappearing pattern: infant stepping reflex at 6 weeks |
|
|
Systems Theory / Dynamic Systems Theory
|
Task, environmental, and organismic constraints
Provides link between local parts and global (function) levels of disablement models |
|
|
Constraints: Physical and Psychological
|
Physical Domain: Task + Environment + Organism = Coordinated Movement pattern
<---Task Selection ---> Psychological Domain: Action capabilities (Effectivities)+ Perception (Affordances) + Cognition, Motivation, Personality |
|
|
Affordances (Perception)
|
Opportunity for action as perceived in the environment
|
|
|
Action Capabilities (Effectivities)
|
Things that you can do; Functions you can perform
|
|
|
Cognition, Motivation, Personality
|
How you feel, what you want to do, decision making
|
|
|
Task Constraints
|
Goals of actions
Performance depends on: -Reinforcement source (type of reward associated with performing the task) -Demands made upon the movement pattern |
|
|
Reinforcement Source
|
Type of reward
Extrinsic reward: obtained with reference to externally defined goals (height of pole vault, the time to swim, etc). Intrinsic reward: obtained with reference to "inner" defined goals-- satisfaction, joy, or feel of moving through the action |
|
|
Demands
|
Extrinsic rules: relationship between movement pattern and external rules (Ex. swim strokes, gymnastic vaults, etc)
Intrinsic processes: shock absorption, pain reduction, economy of effort |
|
|
Environmental Constraints
|
Physical: gravity. barriers, steps, traffic, surfaces
Social: peer groups, cultural normas |
|
|
What do mimes do?
|
Create movement patterns that lead an observer to believe in the presence of environmental constraints that are not actually there
|
|
|
Ecological Psychology theory
|
James Gibson
Mutual fit between organism and environment Perception-Action Coupling |
|
|
Nicolai Bernstein's theory
|
coordination and regulation of movement
mechanical system in a physical environment Desired movement patterns depends on creating the total amount of force: active forces complement passive forces!! Ex. passive walking robots biomechanics and current set of environmental constraints create coordinated pattern |
|
|
Self-optimizing theory
|
Satisfying constraints as well as can be done
Integration of everything to perform coordinated movements at a minimal cost to the organism |
|
|
When constraints go bad...
|
Constraints due to task/organism/environment conflict. These conflicts may be the underlying cause of injury
Ex. runner with hyperpronated feet task does not = organism Organism is the problem Ex. ballet dancer with normal anatomical constraints task does not = organism Task is the problem (extreme demands) |
|
|
Perception-Action Coupling
|
Perception (Affordances) and Action (Effectivities) are mutually related to one another
Organism that can walk will want to walk on a surface that affords it 2 types: Action selection or Movement form Perception for action is body-scaled (from jumping through hole) and energy scaled (riser heigh selected is least costly). |
|
|
Action selection
|
Whether a particular action is performed or not depends on the individual's action capabilities (effectivities) as they relate to what the environment offers (affordances).
Choice/decision to jump over, climb over or walk around a barrier depends on barrier height. If too high, won't do the action |
|
|
Movement form selection
|
Normal walk or ducking down or twisting sideways as go through doorway depends on height and width of passageway
Grip type depends on size and/or weight of object |
|
|
Self Optimization: Gait
|
Preferred stride frequency during gait:
At a given running speed, there is an optimal stride frequency |
|
|
Gait Transition and Self Optimization
|
Horse Study:
-Walk -Trot -Gallop What controls transitions between each stride? (self-organized) Body realizes that the transition will make it easier (in terms of metabolic costs) impact is getting stronger (lots of energy on joints as get faster in each stage) when no load, impact force takes less time to increase with speed. with lots of load, impact force quickly increases with speed. no matter the load, horse transitions at the same point. both oxygen and impact force can have an effect on the horse surface can effect impact force more (ex of situation). both are constraints |
|
|
Systems/Constrains Theory: 3 Short Comings
|
1) Does not give tools to under than different level of disablement
2) Does not tell us how to construct coordinative structure that transform local pieces into global function levels (body parts to special purpose devices) 3) Does not tell us how self-organization can occur (as opposed to top-down control by homunculus) |
|
|
Dynamics
|
Changes in behavior over time
|
|
|
System
|
a regularly interacting or interdependent group of items forming a unified whole
|
|
|
Dynamic System
(Theory) |
A system who behavior changes over time
Theory: concerned with the laws or rules that govern the changes in system behavior over time |
|
|
Dynamics, Self-Organization, Infinite Regress
|
Self organization underlies the motion patterns of human and non-human biological systems
Ex. Human locomotion (Wagenaar): arms and legs prefer to move in different patterns relative to one another when walking at slow vs. normal speeds Ex. Taylor Couette Flow Regular layers-- wavy layers--- turbulence |
|
|
Gluteus max weakness
|
Impact at heel strike creates hip flexion torque.
Glut max creates hip extension torque. If glut max is weak, the torso will be thrown into flexion at heal strike and balance will be lost. But with compensatory extension posture, the induced flexion moment is reduced and balance is maintained |
