54 terms

Motor Development and Motor Behavior of the Lifespan

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Motor control
the ability to regulate or direct the mechanisms essential to movement
emergence of movement constrained by
task, individual, environment
The individual
movement arises from the interaction of multiple processes such as perception, cognition, action
perception
is essential to action it is the integration of sensory impressions into psychologically meaningful information it includes both peripheral sensory mechanisms and higher level processing
cognition
can include motivation, attention, emotion
The individual 2
It is assumed that the body operates in "functional collectives" or "coordinative structures" within a finite and limited class of movements and by doing such controls the derees of freedom problem
the individual 3
sensory/perceptual systems provide info about the state of the body and features within the environment critical to the regulation of movement
The task functional categories
bed mobility, transfers, dressing
discrete task
definitive beginning and end ie: kicking a ball, standing from sitting
continuous task
the end point is arbitrary ie running walking
characteristics of the base of support
stable: nonmoving base of support
mobile: moving base of support
The task
1.functional categories
2. descrete vs continuous
3.characteristics of the base of support
4. The presence of manipulation
5. movement variability
open movement task
constantly changing and unpredictable
closed movement task
relatively stereotyped, little variability, fixed predictable environments
open-loop motor control
no sensory feedback necessary
closed-loop motor control
afferent information guides movement
The environment
regulatory and nonregulatory, features of the environment can enable or hinder movement
Regulatory
aspects of the environment that shape the movement itself (size, shape, weight of cup)
Nonregulatory
may affect performance but movement does not have to conform to these features (background noise)
Theory
set of interconnected statements that describe unobservable structures or processes and relate them to each other and to observable events
theories provide
a framework for interpreting behavior, a guide for clinical action, new ideas, working hypotheses for examination and intervention.
Reflex theory
Sherrington: complex behavior could be explained through the combined action of individual reflexes that are chained together
Reflex theory 2
a basic premise was that physical events occuring in the environment served as the stimulus for action, triggering a chain of individual reflex circuits that were responsible for producing a movement response
reflex theory limitations
the theory was too simple to account for a person's ability to perform a wide variety of goal-directed actions especially those requiring anticipation
How did reflex theroy influence PT
clinical strategies to test reflexes should allow PT to predict function, movement behaviors interpreted in terms of prescence or absence of controlling reflexes, enhance or reduce effects of reflexes to retrain motor control
Heirarchical theory
cortical centers solely control movement planning and execution. It directs lower centers with the NS. Reflexes are part of the heirarchy of motor control
Hierarchical Theory 2
representations of movement are stored in memory in the form of plans or programs for movement. These consist of preconstructed sets of motor commands that are constructed at the highest cortical levels and then conveyed to the lowerst centers.
Schaltenbrand
used these concepts to explain the development of mobility in children and adults - appearance and disapperance of a progression of hierarchically organized reflexes
Weisz
reported hierarchically organized reflex reactions that he thought were the basis for equilibrium in humans, proposed relationship between the dev of these reflexes and the dev of sitting standing and walking
Gesell and McGraw
applied current scientific thinking about reflex hierarchies of motor control to explain the behavior they observed in infants
Neuromaturational Theory of Development
Gesell and McGraw normal motor development was attributed to increasing corticalization of the CNS-resulting in the emergence of higher levels of control over lower level reflexes
heirarchical theory current concepts
it has been modified, each level of the nervous system can act on other levels depending on the task, reflexes not the sole determinant of motor control but one of processes important to the control of movement
central motor pattern
more flexibile than a reflex - it can be either activated by sensory stimuli or by central processes.
example of central motor pattern
locomotion in cats with sensory info cut at SC they could still produce locomotion patterns
motor programming theories
sensory input is not necessary for movement but does modulate movement
clinical implications of motor programming theories
intervention should focus on retraining movements important to a functional task, not just reeducating specific muscle sin isolation
Limitations of motor programming theories
CPG cannot be considered the sole determinant of action
Nicolai Bernstein
Systems theory
Systems theory
considers not just the nervous system but also the musculoskeletal system and the forces acting on the body, the same central command could result in different movement patterns and different commands in the same patterns
Systems theory 2
coordination of movement is the process of mastering the redundant degrees of freedom
synergistic control of movement
systems theory - muslces are constrained together to act as a unit
systems theory limitations
broades theory and does not focus heavily on the interaction of the organism and the environment
Systems theory clinical contributions
most consider not only the CNS but also the msculoskeletal system as a determinant of motor control, examination and interventaions for patients with neurological impairment must look at the whole body and the interactions of multiple body systems
Principle of self organizaton
Dynamic action theroy - when a system of individual parts come together, its elements behave collectively in an orderly way, there is no need for a higher unit to issue instructions
Principle of nonlinear behavior
dynamic action theory - a new configuration of the behavior emerges when a single parameter reaches a critical value ie: walk, trot, gallop control parameter is velocity
Control parameter
dynamic action theory - a variable that regulates change in the behavior of the entire system
attractor states
dynamic action theory - preffered patterns of movement used to accomplish common activities of daily life
attractor well
dynamic action theory - the degree to which there is flexibility to change a preferred pattern of movement
dynamic action theory limitations
neural contributions to movement are understated
dynamic action theory clinical implications
movement is an emergent property - it emerges from the interaction of multiple elements, understanding the physical or dynamic properties of the human body is important in treatment
Gibson
Ecological theory
ecological theory
perception guides actions, perception focuses on detecting information in the environment that will support the actions necessary to achieve the goal
ecological theory 2
the individual is an active explorer of the environment - the idividual is able to detect, through perceptual process, meaningful intrinsic and extrinisc information that can be used to organized actions
ecological theory clinical implications
the ability to develop multiple solutions to accomplishing a task requires that the patient explore a range of possible ways to accomplish a task and discover the best solution given their circumstance