Motor Control And Learning Flashcards
Movement
Functional objective that must be achieved in order to accomplish the overall goal of an activit
Motor control
Ability to regulate or direct mechanisms essential to movement - CNS organizes individual muscles/joints into one coordinated functional movement
Movement emerges from
Interaction of individual, task, and enviro
-generates movement to need demands of task and enviro
Motor control requires
Action
Perception
Cognition
Perception
Integration of sensory impressions into psychologically meaningful information
-both sensory and perceptual systems along w/ higher level processing
Cognition
Attention, motivation, emotional aspects of motor control that underlie the establishment of intent or goals
Motor programs
Communications in CNS that are based on past experiences and can generate planned postural adjustments and movements
Sub programs
Learned parts that act as motor commands for more automatic routines
The more complex the movement,
The more cortical networks involved
- all areas of brain are directly or indirectly involved in motor control
- inter connectivity b/n cortical areas will impact movement
Lateral corticospinal tract
Distal muscles, precise movements
Planning of voluntary movements
Anterior corticospinal tract
Axial (trunk) muscles, uncrossed fibers
Corticospinal pathway origins - 4
4 PRimary motor cortex - 1/3 to face/hand/rest of body. Selectivity, skill, precision
Corticospinal pathway origin - area 6
supplementary motor, premotor cortex - adjusts the manner in which spinal cord responds to the peripheral input
Corticospinal pathway origin - area 312
Primary somatosensory/ 5,7 somatosensory association
Adjust transmission of the sensory pathways including stereognosis and discriminatory sensation
Corticospinal pathways
Direct active movement control
- fine tuning of volitional movement, esp skilled indep finger control
- Skill and precision by incorporating visual and auditory information
- rate and rhythm of automatic movements
- speed and agility —>rapid skilled movements
Basal ganglia
Inter connected gray matter nuclear masses- direct connection to limbic, frontal cortex, brainstem
- planning and programming movement (selection and inhibition of motor strategies)
- important role in cognitive processes, awareness of body orientation, adapt behavior to task changes/motivation
Cerebellum
Integrative structure critical for environmental adaptations
-compares ongoing movement w/ the motor command from the cortex
Primary motor areas
Receive somatopic projection from somatosensory cortex
- input is from muscle spindles, sensory side to stretch reflex
- neurons correlates w/ a wide variety of movement parameters including force, velocity, direction
Secondary motor areas
Supplementary and premotor areas
Planning movements, neurons fire hundreds of milliseconds before a movement begins
Supplementary motor area
Crucial for performing complicated tasks involving both sides of the body (two handed activities)
- complex sequences previously learned form memory in absence of visual cues
- more active in sequential motor task
Premotor area
- Planning movements that require sensory cues
- Receives large input form posterior parietal cortex
- Provides sensory input for targeted areas and action is context specific
- projections into SC
- planning and initation of centrally programmed commands
- establishment of the postural set
Premotor area involved
In activities that require sequencing of goal directed info
-Less active during repetitive simple movements
Primary somatosensory area
After movement starts
Responds to Sensory feedback
Info via thalamus
Multiple sensory fields respond specially to a somatosensory input
Project to SC, BS, thalamus (control input to cerebral cortex)
Both the somatosensory motor and pre motor cortex
Are active during learning a motor task!!
Premotor vs somatosensory
Premotor - movements that rely on sensory inputs from enviro (vision and proprietary). Respond to changes in sensory input during complex movement or perturbations
Somatosensory - active in skills that require planning several movements ahead, particularly at that require temporal ordering of proximal and distal movements
Voluntary movement
Intentionally, guided by perception
-planned then executed by output of motor commands (correct sequence of muscle activation)
Sensory feedback to optimize performance
Requires postural support
Modulation of voluntary movement
Motor cortex alters it’s output depending on its afferent input
- pyramidal tracts active before movement - contribute to establishment of postural set
- allows feedback and feed forward loop
Motor cortex damage
- deterioration in ability to make find indep. Movements of hand
- contralateral loss of hand orientating responses
- disruption of sensory motor linkage, esp spatial adjustments
- destruction of internal capsule
General motor cortex damage - destruction in internal capsule
Contralateral hemiplegia initially flaccid, later spastic
Most marked in distal muscles
General lesion in primary motor area
Muscle paresis spasticity and difficulties w/ multi-joint movements on same side of face and contralateral side of body
General lesion premotor area
Similar in presentation to primary
- involves more proximal weakness (hip, shoulder)
- motor planning skills affected
- bilateral activities affected
General lesion - supplementary motor cortex
Bilateral arm and hand movements
Most apparent not during visually guided movements but during movements based on patterns or sequences
-akinesis: loss of planning for movement control
General lesion - primary somatosensory area
Contralateral sensory loss
Stereognosis
Limb position sense can be affected- sensory ataxia during attempted limb movements
How to be most affective w/ pts w/ deficits (motor control)
- Most interesting things to CNS- new and novel
- Produce stimulus significant to pt that relates to their CNS at moment in time to allow for integration
- Individual differences: some repsond to cognitive, some sensory
Motor control theory: Reflex theory
- Reflexes are building blocks of complex behavior,
- complex behavior: combined action of individual reflexes chained together
Motor control theory: Reflex theory limitations
Reflexes must be generated by outside agent
Doesn’t explain spontaneous and voluntary movement, movement that occurs in absence of sensory stim, fast or novel movements
Motor control theory: hierarchical theory
- Defined organization in top down matter
- successively higher centers of NS exert control over level below it
Motor control theory: hierarchical theory limitations
Doesn’t explain certain behaviors such as stepping on a nail causing pain which results in immediately flexor withdrawal - ie bottom up control
Motor programming theories
- Based on physiologists of action (not reactions)
- central motor program that can be activated by sensory stim or central process
- research w/ cats
- defines central pattern generator
Motor programming theories: systems theory
Looked at whole body as mechanical system:
Subject to mechanical forces such as gravity and inertial forces
-showed same central command can result in quite different movements because of interplay b/n external forces and variations in initial conditions of task
Motor programming theories: dynamic systems
- self organization where system of individual parts comes together and its individual elements behave collectively in an ordered way
- no need for higher center to issue instructions
- movements that are stable are less likely to change vs movements that are unstable
Motor control theories: dynamic systems - change occurs
based on change in one of the systems, control parameter: variable that controls behavior of entire system
Motor control theories: ecological theory
Most effective way for our motor systems to interact w/ environment in order to perform a goal directed behavior
- how enviro info used to guide movements
- *action requires perceptual info to produce goal directed task in a specific enviro
Which motor control theory is best?
Combo of all theory - no one theory explains all movements
-evolution of systems approach which is interaction of individual, task, enviro
Neurofacilatory approaches
50s-60s - tx the movement dysfunction of CNS lesion by attempting to affect CNS by manipulation of sensory input
Neurofacilatory approach types
NDT PFN Brunnstrom SI DNS
Old assumptions about neurofacilitation
-top down model of control emergence of behaviors organized w/ sequentially higher levels of NS
-driven by sensory input
-cortical lesions —> release of abnormal reflex—> constrained individuals ability to move
Abnormal movement direct result of lesion
Old assumptions about neurofacilitation - recovery
recovery requires higher centers to gain control of lower centers - should occur in same developmental sequence
- functional skills will return once abnormal movement is inhibited
- repetition of normal movement will automatically transfer to functional task
Rehab and motor control today
Abnormal movement is individuals best solution to solving a problem given current state of NS and surrounding peripheral structures
- not just a result of lesion itself
- emphasis on training normal movement patterns
- decreased time spend on inhibiting abnormal patterns
- consider motor learning principles
