Theories of Motor Control Flashcards
Theories of motor control
reflex theory hierarchical theory motor programming theory Bernstein's systems theory ecological theory task-oriented perspective dynamic systems theory
Why understand motor control?
- framework for interpreting behavior
- guide for clinical practice
- facilitate new ideas
- working hypotheses for examination & intervention
reflex theory
Older theory that has been surpassed but is useful for understanding one element of motor control. Reflex is a way to create movement, need sensory stimulation to drive normal behavior. Some reflexes can be useful within more complicated voluntary motor behaviors. Reflexes are used in motor control.
reflex theory assumptions
- reflex is a basic unit of behavior
- complex movement is produced by the summation of reflexes
- sensory inputs control motor output
- sensory stim drives & is necessary for normal movement behvaior
reflex theory limitations
- we can override reflex activity
- with fast movement, there is not enough time to process sensory feedback before the next movement must be initiated.
- coordinated movement is possible without sensory stim
- single stimulus can result in variety of outcomes dependent on contex
- can’t explain how new movements are produced
reflex theory clinical implications
Use of facilitatory and inhibitory techniques to:
- stimulate reflexes in order to facilitate tone for flaccid extremities
- desensitize periphery to stimuli in order to reduce reflex activity & inhibit spasticity
- neither approach works well at increasing functional movment
hierarchical theory
Recognizes the CNS has multiple levels, reflexes still exist but higher control centers could override reflexes when needed & at times the higher control is needed to make movement
hierarchical theory assumptions
- CNS organized top-down
- to perform voluntary movements, higher centers must inhibit lower-level reflexes
- development of mobility in infants parallels “corticalization” of CNS & corresponds with appearances & disappearance of reflexes that are organized at progressively higher levels of the hierarchy
- pathology of higher centers said to release primitive reflexes from inhibition to abnormal voluntary movement
hierarchical theory limitations
- does not explain why low-level reflexes prevail in adults in certain situations
- does not explain much about how voluntary movements are controlled
- does not explain evidence of ‘bottom-up’ control within CNS
hierarchical theory clinical implications
traditional neurotherapeutic approach
Used reflex/hierarchical theory of motor control as rational for:
- abnormal motor behaviors seen in pt with CNS damage
- need to work thru developmental sequences of mobility before training functional movements
- benefits of sensory stim to facilitate movement patterns
hierarchical theory clinical implications
more recent interpretations
Recognize the flexible, multi-directional, control across levels of the CNS
- use of facilitation/inhibition techniques to address particular sensory abnormalities, develop some basic patterns of coordination
- integrates those techniques with explicit training in functional tasks that use similar patterns of movement or sensory stim
motor programming
Voluntary input to control movement. Schemas are laid out with plans for a whole range of muscles in order to accomplish a task - generalized programs that are tailored to what you need to do today or tomorrow. Movement happens due to intention not only sensory stim
motor programming assumptions
- central motor programs exist that control motor actions
- movement can be initiated by central process or by sensory stimulation
- motor program represents task/motor behavior in abstract terms
- generalized motor program stores general rules for movement but certain aspects of movement can vary
motor programming limitations
- focus entirely on CNS control & initiation of movements without integrating knowledge of reflex actions & other levels of CNS control
- does not explain how changes in task content or environmental impact movement & its control
motor programming clinical implications
- this approach supports importance of helping patient relearn proper rules for movement
- focuses intervention on relearning functional movements vs. reeducation of specific muscles
