Motor Control Flashcards
What does movement emerge from?
Interaction of individual, task, and environment
What is motor control?
The ability of regulate and direct the mechanisms essential to movement - the study of postures and movements and the functions of mind and body that govern posture and movement
What is emerges from “task”?
Mobility, stability, and manipulation
What emerges from “individual”?
Cognition, perception, and action
What emerges from “environment”?
Regulatory and nonregulatory
What are examples of movement and action?
Walking, running, talking, smiling, and reaching
What is the relationship between performing a task and degrees of freedom?
When we first perform a task, we decrease our degrees of freedom and as we learn to conquer the movement, we increase our degrees of freedom
What is an example of movement and perception?
Walking into a well lit room versus a dark room
What is cognition?
Attention, planning, problem solving, motivation, emotions, and intent
What are “task” restraints on movement?
Recovery of function - sensory/perceptual impairments, motor impairments, and cognitive impairments
What are examples of functional task groupings?
Bed mobility, transfers, and ADLs
What are examples of discrete tasks?
Kicking a ball, throwing, and striking a match
What are examples of continuous tasks?
Running, swimming, and steering a car
What is the difference between discrete and continuous tasks?
Discrete tasks have a beginning, middle, and end - continuous tasks have no distinct beginning or end
What is the difference between stability and mobility tasks?
Nonmoving base of support versus a moving base of support
How do attention demands change regarding mobility activities?
Increase with mobility activities
What are manipulation components regarding task constraints?
Standing, standing lifting light load, and standing lifting heavy loads
How does adding manipulation change with task demands?
Increases the task demand
What are two types of movement variability?
Open movement (ex: soccer/tennis) and closed movement
What are two types of environmental constraints?
- Regulatory - size, shape, and weight of cup/ type of surface we walk on
- Non-regulatory - background noise and presence of distraction
Why is it important to study motor control?
(Re)train clients to move better and to teach the typical motor patterns
What is the reflex theory?
Reflexes building blocks of complex behavior and combines action of individual reflexes chained together
What were the problems with the reflex theory?
Reflex requires an external stimulus, some movements occur without sensory stimuli, some movements occur too rapidly for sensory feedback to trigger follow up movement, chain theory does not account for need to override reflexes to achieve goal, and reflex chaining does not allow for production of novel movement
What was the second theory?
Hierarchical theory
What is the hierarchical theory?
Brain has higher, middle, and lower levels of control - top down control
What did Rudolf Magnus theorize?
Found reflexes controlled by lower levels were present only when higher cortical levels are damaged - reflex testing
Who furthered the hierarchical theory?
Georg Schaltenbrand in 1928
What did Georg Schaltenbrand theorize?
Explained the development of mobility in children and adults - appearance and disappearance of hierarchically organized reflexes
Who was the third person to further the hierarchical theory?
Gesell and McGraw in 1940
What did Gesell and McGraw theorize?
Maturation of infants, normal motor development attributed to increased cortical control over the lower level reflexes, and the CNS is the primary agent of change in development
What is ATNR?
Asymmetric tonic reflex - used with babies
What is the cortex responsible for regarding posture and motor?
Posture - equilibrium reactions
Motor - bipedal functions
What is the midbrain responsible for regarding posture and motor?
Posture - righting reactions
Motor - quadrupedal function
What is the brainstem/spinal cord responsible for regarding posture and motor?
Posture - primitive reflex
Motor - apedal function
What were the problems with the hierarchical theory?
Cannot explain the dominance of reflex behavior in certain situations in normal adults - withdrawal reflex (ex: stepping on a nail) and bottom up control
What did Brunnstorm theorize?
Pioneer in early stroke rehabilitation who used reflex hierarchical theory to describe disordered movement following a motor cortex lesion
What did Bobath theorize?
NDT - neuro developmental treatment
What is the motor programming theory grounded in?
Physiology of actions within the CNS
What is the central pattern generator (CPG)?
Concept emerged when the response was uncoupled from the stimulus - ex: gait - walking is hardwired in our system/movements required for ambulation exist at birth
What are the aspects of the multidisciplinary development of the motor programming theory?
Clinical, psychological, and biological backgrounds
What is an example of rhythmic pattern generator?
Interrupting afferent input did not cease insects ability to beat their wings
What are factors of the motor programming theory?
Explore the physiology of actions rather than the physiology of reactions and may be used to represent neural connections that are stereotyped and hardwired or to describe the higher level motor programs that represent actions in more abstract terms
What are the limitations with the motor programming theory?
CPG concept was never intended to replace the concept of the importance of sensory input in controlling movement, a CPG cannot be described to be the sole determinant of action, and DOES NOT TAKE INTO ACCOUNT that the nervous system must deal with both musculoskeletal and environmental variables in movement control
What are the clinical implications regarding the motor programming theory?
Allow clinicians to move beyond a reflex explanation for disordered motor control, suggests the importance of helping patients relearn the correct rules for action, and intervention should focus on retraining movements important to a functional task
What is the importance in the abstract motor program?
Right and left muscles are synergists
What is the most recent theory of motor program?
- Abstract representation of movement sequence that is store in memory and consists of variant and invariant features - Schmidt 1989
- Higher-level hierarchically organized neural processes that store the rules for generating movements - Shumway-Cook and Woollacott
What are examples of CPGs?
Locomotion, respiration, and swalling
What is the next theory regarding motor control?
Systems theory
What did Nicolai Bernstein theorize?
Characteristics of the system and the forces acting on the system are as important as the neural control of the movement itself
What two ideas does the systems theory focus on?
Degrees of freedom and synergies
What is the systems theory?
Distributed model of motor control in which central commands are modified by the forces acting upon the system
What is the relationship between synergies and DOF?
Synergies decrease redundancy within the system which in turn decreases the DOF - creates smooth movement
What is the emergent property of the systems theory?
Movement
What is the systems approach?
Recognizes that movement emerges from an interaction between the individual, task, and environment - movement results from dynamic interplay between perception, cognition, and action systems
What are the six factors surrounding tasks/goals? (picture)
Comparing systems, MS systems, SS systems, commanding systems, regulation systems, and environmental systems
What are the limitations with the systems theory?
Does not focus as heavily on the interaction of the organism with the environment as do some other theories of motor control
What are clinical implications regarding the systems theory?
- Stresses the importance of understanding the body as a mechanical system
- Examination and intervention must focus not only on impairments within individual systems, but the effect of interacting impairments among multiple systems
What is the dynamic action theory?
When a system of individual parts comes together, its elements behave collectively in an ordered way to produce emergent behaviors
How does movement emerge regarding the dynamic action theory?
Change in a control parameter
What are the preferred patterns of movement for the dynamic action theory?
Attractor states
What is an example of a control parameter?
Velocity
What is important about the dynamic action theory?
Higher centers are not needed
What kind of system is the dynamic action theory?
Self-organizing system
What are limitations with the dynamic action theory?
- Nervous system has a fairly unimportant role
- Relationship between the physical system of the animal and the environment in which it operates primarily determines the animal’s behavior
What are the clinical implications of the dynamic action theory?
- Movement is an emergent property
- By understanding more about the physical or dynamic properties of the human body, clinicians can make use of these properties in helping patients regain motor control
Compare and contrast the motor program theory and dynamic systems theory regarding variability of movement.
Motor program theory - variability is a consequence of error
Dynamic systems theory - variability is necessary of optimal function
…See slide #52
What can too little variability lead to?
Injury
What can too much variability lead to?
Impaired movement performance (ex: ataxia)
What do stable patterns of movements become when transitioning to a new movement pattern?
Unstable
What is a control parameter in the Bernard instability example?
Heat
Are humans far from equilibrium?
YES - encourages self-organization
What does learning in humans involve?
Destabilization of one pattern so that a new pattern of stability may be found
What is the order pattern in the equilibrium examples?
Macroscopic description of the emergent behavior pattern (ex: hexagons and/or turbulence)
How are behavior patterns expressed?
By order parameters
What does the order parameter lose when the control pattern alters?
Stability
What is the ecological theory?
Actions require perceptual information that is specific to a desired goal-oriented action performed within a specific environment - broadened understanding of nervous system function as perception/action system
What does perception focus on regarding the ecological theory?
Detecting information in environment that will support actions necessary to achieve the goal - have to see patient in their natural environment to affect change in behavior or motor skills
What is the order of the ecological system from the center outwards?
You, microsystem, mesosystem, exosystem, macrosytem, and chronosystem
What consists of the microsystem?
Family, school, peers, religious affiliation, workplace, and neighborhood
What consists of the mesosystem?
Same as microsystem
What consists of the exosystem?
Economic system, political system, education system, government system, and religious system
What consists of the macrosystem?
Overarching beliefs and values
What consists of the chronosystem?
Dimension of time
What are limitations regarding the ecological theory?
Research emphasis has shifted from the nervous system to the organism/environment interface
What are the clinical implications regarding the ecological theory?
Individual is an active explorer of the environment and the individual can develop multiple ways to accomplish a task
What is important regarding the ecological theory?
Adaptability
What is the definition of posture?
Static position of any body segment
What is the definition of movements?
Transition from one posture to another
What theory of motor control is the best?
Theory that combines elements from all theories
What does scientific theory provide?
Framework that allows integration of practical ideas into a coherent philosophy for intervention
What does clinical practice evolve in parallel with?
Scientific theory
What type motor control model is the most current?
Systems theory
What is neurofacilitation?
Retraining motor control through techniques designed to facilitate and/or inhibit different movement patterns
What is neurofacilitation associated with?
Reflex and hierarchical theories of motor control
What is movement organized around?
Behavioral goal
What is movement constrained by?
Environment
How do patients learn?
By actively attempting to solve the problems inherent in a functional task rather than repetitively practicing normal patterns of movement
What is memory?
Acquisition of knowledge or ability - product of the learning process
What type of memory is the working memory?
STM
What type of memory is evidence of learning?
LTM
What is strategy?
Combination of sensory information from the environment (afferent input) with the synergy (efferent output)
What is synergy?
Muscles firing in a pattern to return to equilibrium
What is feedback?
Any form of augmented, post-response information about the achievement of a goal
What is feedforward?
Information to prime the system - setting self up to pick up a heavy object
What is perception?
Integration of sensory impressions into meaningful info - adds interpretation and meaning to afferent information
What is a control parameter?
Variable that causes change in a pattern
What is an order parameter?
Incorporates and characterizes all the systems that cooperate to produce a movement
What is a steady state?
Homeostasis of a system
What are degrees of freedom?
Number of variables of a system that corresponds to the number of parameters to fully describe the task - how many joints that are involved in a movement
