1. Somatic Motor System
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2. 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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3. Overview of the Somatic Motor system Praxis
Clinical signs related to the Somatic Motor system
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4. Somatic Motor System overview
Interactions of the sensory and motor systems enable voluntary movement
You have learned about these sensory and motor pathways earlier in this class!

6. Somatic
Motor
System
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.

7. corticoreticulospinal & vestibulospinal
Exit circuitry:
Corticoreticulospinal
& Vestibulospinal
pathways
- control of trunk muscles; posture
corticoreticulospinal & vestibulospinal

8. corticospinal Exit circuitry: Corticospinal pathway
- finely tuned hand movements
corticospinal

9. corticorubrospinal Exit circuitry: Corticorubrospinal pathway
- limb movements
corticorubrospinal

10. corticobulbar Exit circuitry: Corticobulbar pathway
finely tuned movements of the face & head
Somatic Motor menu

11. Overview of the Somatic Motor system Praxis
Clinical signs related to the Somatic Motor system
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12. Praxis praxis 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!

13. Praxis
Depends upon multisensory input

14. Praxis Depends upon multisensory inputs
Allows multiadaptive responses in context
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15. Overview of the Somatic Motor system Praxis
Clinical signs related to the Somatic Motor system
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16. Somatic Motor Clinical signs
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Position sense test
Clonus
Babinski sign
Enhanced deep tendon responses
Spasticity
Clasp knife response 1 2 3 4 5 6
Clinical Signs
Signs

17. Position sense
Play
Movie
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.
Clinical Signs
Signs

18. Clonus
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Movie
A series of fast, involuntary contractions symptomatic of damage to upper motor neurons.
Clinical Signs
Signs

19. Babinski reflex
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Movie
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.
Clinical Signs
Signs

20. Enhanced Deep Tendon Reflexes
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Movie
An unusually vigorous patellar tendon reflex may be observed following upper motor neuron damage, often in conjunction with heightened muscle tone (spasticity) and clonus.
Clinical Signs
Signs

21. Spasticity
Play
Movie
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.
Clinical Signs
Signs

22. Clasp knife response
Play
Movie
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.
Clinical Signs
Signs

23. Somatic Motor system tutorial!
That ends the
Somatic Motor system tutorial!
Somatic Motor menu