Lec 5 Flashcards
Motor Control
the ability to regulate or direct the mechanisms essential to movement
information processing that organizes the musculoskeletal system to create coordinated, goal-directed movement
feed-forward and feed-back strategy
movement emerges from the interaction of three factors
individual
task
environment
Constraints on movement: individual
action, cognition, perception
Action (Individual)
body is characterized by a high number of muscles and joints, all of which must be controlled during the execution of coordinated, functional movement
degrees of freedom problem
choosing among equivalent solutions and then coordinating the many muscles and joints involved in a movement
Perception (Individual)
integration of sensory impressions into psychologically meaningful info
info about state of body and the environment
peripheral mechanism and higher-level processing that adds meaning to afferent info
Cognition (individual)
attention, planning, problem solving, motivation and emotional aspects of motor control
single vs dual task control
running on a treadmill vs being in the school with shoving and carrying things
move functionally with many demands on the body systems
Task
nature of task being performed determines the type of movement needed so several classification parameters have been developed
understanding the nature of the tasks can provide a framework for functional evaluation and can serve as a progression for retraining functional movement
Task Classification; functional categories
bed mobility tasks
Transfer tasks
Walking and ADLs
Task Classification; critical attributes that regulate neural control mechanisms DISCRETE VS CONTINUOUS
discrete - definite beginning and end
continuous - no recognizable beginning and end points, end point is not an inherent characteristic of task (walking, running, swimming)
Task Classification; stable vs in motion
stability; stable base of support
mobility - moving base of support
task classification; whether object manipulation is required
sequenced task - increase the demand for stability (standing and lifting)
Task classification; movement variability
open - constantly changing or unpredictable environments (crossing busy street)
closed - relatively fixed, predictable environments (getting on and off toilet)
Environment
classified by whether features of the environment shape the movement itself
regulatory - movement must conform to regulatory features in order to achieve the goal of task (ex; different sized cups require different grasping patterns; walking on an uneven grassy surface impacts the gait pattern differently than walking on smooth floor) *these features shape the movement itself
non-regulatory; movement does not have to conform to these features, may or may not affect movement (background noise, lighting)
Systems Theory
describes the body as a mechanical system with many degrees of freedom that need to be controlled
hierarchical control exists to simplify control of many DFs; higher level of nervous system activate lower levels, which activate synergies (group of muscles)
as demands of a task increase, control signals to synergy increase (parallel increases in activation in all muscles) if you start juggling, youre going to need more synergies invovled
Systems theory: Movement emerge from __
interplay between the body system, external force, and variations in the initial condition
same central command can result in different movements
different commands could result in the same movement
Dynamic systems theory
- similar to systems theory but de-emphasizing the notion of commands from CNS in controlling movement and seeking physical explanations
self-organization (systems come together in an ordered way, dont need higher center for commands)
- new movement emerges because of a circitcal changes in one of the systems called controlled parameter (ex; velocity)
*variability
Dynamic systems - Variability
variability is not considered to be the result of error but rather a necessary condition of optimal function
optimal variability provides flexible, adaptive strategies and allows for adjustments to environmental changes
too little variability can lead to injury, too much can lead to impaired movement (ataxia - walking with limbs all over the place, on and off)
small amount of availability indicates a highly stable behavior or a preferred pattern viewed as attractor state
Dynamics system - Attractor well
the deeper the well, the harder it is to change preferred pattern, suggesting a stable movement pattern
less ability to have variability
controlled parameters
a variable that regulates changes the behavior of the entire system
Theoretical framework
theoretical framework is the basis for clinical methods related to examination and intervention in patients with neurological and ortho problems (any problems!)
theory helps us to generate research questions and hypothesis about the nature and cause of movement