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Somatic Motor Systemmodule

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Somatic Motor menu

Somatic Motor system

Overview of the Somatic Motor system

Praxis

Clinical signs related to the Somatic Motor system

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Somatic Motor system

Overview of the Somatic Motor system

Praxis

Clinical signs related to the Somatic Motor system

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overview

• Interactions of the sensory and motor systems enable voluntary movement

• You have learned about these sensory and motor pathways earlier in this class!

Somatic MotorSystem

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Somatic MotorSystem

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Internal motor systems (cerebellum & basal ganglia) must be effective for functional motor output to take place.

Exit circuitry (motor output pathways) also must be effective for functional motor output.

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corticoreticulospinal & vestibulospinal

Exit circuitry:

Corticoreticulospinal& Vestibulospinal pathways

- control of trunk muscles; posture

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corticospinalExit circuitry:

Corticospinal pathway

- finely tuned hand movements

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corticorubrospinalExit circuitry:

Corticorubrospinal pathway

- limb movements

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corticobulbarExit circuitry:

Corticobulbar pathway

- finely tuned movementsof the face & head

Somatic Motor menu

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Somatic Motor system

Overview of the Somatic Motor system

Praxis

Clinical signs related to the Somatic Motor system

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• The ability to produce a NEW motor response

• Describes earlier phases of the motor learning process, NOT the execution of a learned or practiced motor pattern

• Once a motor act is practiced & learned, it NO LONGER requires praxis!

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• Depends upon multisensory input

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• Depends upon multisensory inputs

• Allows multiadaptive responses in context

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Somatic Motor system

Overview of the Somatic Motor system

Praxis

Clinical signs related to the Somatic Motor system(next)

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Position sense testClonusBabinski signEnhanced deep tendon responsesSpasticityClasp knife response

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Clinical Signs Signs

Somatic Motor Clinical signs

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Position sensePosition sense

With the client’s eyes closed, the clinician manipulates the client’s right thumb. He is asked to point his left thumb in the same direction as his right thumb. The clinician switches sides and he is no longer able to perform the task.

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Clinical Signs Signs

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ClonusClonus

A series of fast, involuntary contractions symptomatic of damage to upper motor neurons.

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Clinical Signs Signs

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Babinski reflexBabinski reflex

An extension of the great toe, sometimes with fanning of the other toes, in response to stroking of the sole of the foot. It is a normal reflex in infants, but it is usually associated with a disturbance of the pyramidal tract in children and adults.

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Clinical Signs Signs

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Enhanced Deep Tendon ReflexesEnhanced Deep Tendon Reflexes

An unusually vigorous patellar tendon reflex may be observed following upper motor neuron damage, often in conjunction with heightened muscle tone (spasticity) and clonus.

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Clinical Signs Signs

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SpasticitySpasticity

The man exhibits spasticity of the right side, while the woman exhibits spasticity of the left side. Note the posture of the affected arm, the swinging of the leg from the hip with reduced range of the knee and ankle joints, and the reduced dynamic balance.

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Clinical Signs Signs

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Clasp knife responseClasp knife response

An animation of the concept, meant to illustrate an initially great resistance to extension of the joint, followed by a gradual “melting” of the resistance as continued, steady pressure is applied.

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Clinical Signs Signs

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That ends the Somatic Motor system tutorial!

Somatic Motor menu