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Motor Control TheoriesAhmed Shawky Ali
Motor Control TheoriesReflex theory
Reflex Theory
Basic structure of a reflex :A-receptorB- conductor C-effector
Reflex Theory
Stimulus applied to muscle results in stereotypical responses referred to as a reflex (peripherally based)-afferent sensory inputs are necessary pre-requisite for efferent motor output .
Reflex Theory
Sherrington, Reflexes are the building blocks of complex motor behaviors or movements.Sherrington belived that, complex behaviors could be occur through combined action of individual reflexes that were chained together.
Reflex Theory
Sir Charles Sherrington, the integrative action of the nervous system (1906) Reflex chaining: complex movements
are a sequence of reflexes elicited together
Limitations of Reflex Theory
Unable to explain:1-Spontaneous and voluntary
movements:Reflex can not be considered basic unit
of behavior as reflex must be activated by an outside agent .
Limitations of Reflex TheoryUnable to explain:2-Movement can occur without a sensory
stimulus:Recent resarch shown that , animals
can move in a relative coordinated fashion in absence of sensory input.
Limitations of Reflex Theory
Unable to explain:3-Fast sequential movements, e.g. typing
As sequence of movement too rapidly to allow for sensory feedback from the preceding movement to trigger the next
Limitations of Reflex Theory•Unable to explain:4- A single stimulus can trigger various responses (reflexes can be modulated)Which depend on context and descending commands ..for example we can override reflexes to achieve a goal . e.g withdrawl of the hand in fire and when your child in fire you may override reflexive withdrawl to pull the child.
Limitations of Reflex Theory
Unable to explain:5-Novel movements can be carried out:As novel movement put together combination of
stimuli and responses .e.g a violenist learned rules for playing the piece
and applied them to new situation .
Clinical implications 1- Clinical straegies which designed to test reflexes
should allow therapist to predict the function .2- Patient movement behavior would be interpreted in
term of prescence or absence of controlling reflexes.3- Reteaining of motor control for functional skills
would focus on enhancing or reducing the effect of various reflexes during motor tasks ( e.g facilitating or inhibiting reflexes & on reducing hypertonicity )
Reflex- and Hierarchical Based Neurofacilitation Approaches
Brunnstrom, Rood, Proprioceptive neuromuscular facilitation (PNF), Bobath’s neurodevelopmental treatment (NDT)Retraining motor control through
“techniques” to facilitate and/or inhibit different movement patterns
Assumptions of Neurofacilitation Approaches
Abnormal movement is a direct result of the neurologic lesion
Inhibit abnormal movement patterns to facilitate the normal movement patterns will lead to the return of functional skills
Repetition of normal movement patterns will automatically transfer to functional tasks