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