1. The Motor System and the Cerebellar Function
Neurologic System
The Motor System and the Cerebellar Function

2. Motor Pathways & Type of Movements
Corticospinal or Pyramidal Tract
Voluntary, skilled, discrete, purposeful (writing)
Extrapyramidal Tracts
Maintain muscle tone and control body movements (walking)
Cerebellar System
Coordinates movement, maintains equilibrium and posture….Operates on subconsious level
Motor nerve fibers in Corticospinal tract originate in cerebral cortex, travel to brain stem, decussation, & move down lateral column spinal cord
What type of movements are mediated by The Corticospinal Tract
Voluntary, skilled ,discrete movement

3. Question for Thought
Describe 3 major motor pathways in the CNS including the type of movements mediated by each?

4. Chapter 21 Cerebral Cortex
The Motor Pathways consist of the 1. Corticospinal or Pyramidal Tract. In center of cerebral cortex. Note upside down human – Red – Hands Motor nerve fibers originate in the motor cortex and travel to the brain stem where decussation happens and they continue down in the lateral column of the spinal cord. This motor system permits very skilled and purposeful movements 2. Extrapyramidal Tracts- lower, more primitive system, maintain muscle tone, and control body movements ( walking)
3. Cerebellar System- Cerebellum motor coordination, equilibrium, balance, posture. Under the occipital lobe it does not initiate movement but coordinates and smooths it.
Figure p. 688.

5. Upper and Lower Motor Neurons
Upper motor neurons
All descending motor neurons that impact on the lower motor neurons
Located in the CNS
Convey impulses from motor areas of cerebral cortex to lower motor neurons in the cord
Diseases = CVA, Cerebral palsy, Multiple sclerosis
Located completely within the CNS= Brain and Spinal cord

6. Upper and Lower Motor Neurons
In the peripheral nervous system
12 cranial nerves
31 pairs of spinal nerves and all branches
Final direct contact with the muscles
Movement translated into action
Reflex arc
Examples = cranial nerves, spinal nerves
Diseases = spinal cord lesions, poliomyelitis, ALS
ALS = amyotrophic lateral sclerosis
Reflex Arc – Reflexes maintain balance, muscle tone, and unconscious control and quick reaction to painful or damaging situations.
Sensory afferent nerve in muscle is stimulated
fibrers carry message to to spinal cord
Synapse with motor neuron
Motor efferent fibers travel to muscle

7. Question for Thought
Differentiate an upper motor neuron from a lower motor neuron?

8. Subjective Data In the Interview
Any shakes or tremors in the hands or face?
Worsen with anxiety, fatigue
Relieved with activity, alcohol
ADL’s affected
Weakness
Where? When? Why?

9. Subjective Data Incoordination Numbness/ Tingling
Balance, falling,
Legs give out
Clumsy
Numbness/ Tingling
Describe ( pins and needles)
Significant past history
TIA’s, Atrial Fib.

10. Assessment of Motor System
Body position
Involuntary movements
Muscle size ( bulk)
Muscle tone
Muscle strength

11. Body Position
Observe during movement
Observe at rest

12. Involuntary Movements
Tremors, tics, fasciculations, myoclonus
Note:
Location
Quality
Rate
Rhythm
Amplitude
Normally no involuntary movements. Can they be controlled at will.
Tremors- involuntary contraction of opposing muscle groups. Rhythmic back and forth movement of one or more joints. All tremors disappear in sleep.
Tics – repetitive twitching of muscle group at inappropriate time –wink, shoulder shrug, head movement
Fasciculations – rapid, continuous twitching of resting muscle or part without movement of limb ( can be seen or palpated… eye)
Myoclonus- rapid, sudden jerk or short series of jerks at regular intervals…Hiccup, arm or leg jerk when falling asleep

13. Involuntary Movements
Note the involuntary movement in relation to :
Posture
Activity
Fatigue
Emotion
Other factors

14. Terms to Describe Movement
Flexion
Extension
Abduction
Adduction
Pronation
Supination

15. More Terms for Movement
Circumduction
Inversion
Eversion
Rotation
Protraction

16. Terms of Movement Continued
Retraction
Elevation
Depression

17. Muscle Size Compare size and contour Atrophy Unilateral/bilateral
Proximal/distal

18. Muscle Tone
A relaxed muscle maintains a slight residual tension referred to as muscle tone.
Hypo tonic, Flaccidity.
Spasticity.
Lead-pipe rigidity.

19. Muscle Strength
Test muscle strength by asking the client to move actively against your resistance or to resist your movement.
A muscle is strongest when shortest and weakest when longest.
Muscle strength should be equal bilaterally and should fully resist your opposing force

20. Terms to Describe Strength
Weakness (paresis)
Paralysis (plegia)
Hemiparesis
Hemiplegia
Paraplegia
Quadriplegia
Impaired strength = paresis
Absence of strength = plegia
Hemiparesis = weakness of ½ of the body
Hemiplegia = paralysis of ½ of the body
Paraplegia = paralysis of the legs
Quadriplegia = paralysis of all 4 limbs

21. Grading Muscle Strength
Scale 0-5
0 - no muscular contraction
1 – slight contraction
2 – Full ROM, gravity eliminated

22. Grading Muscle Strength
3 – Full ROM against gravity
4 – Full ROM against gravity, some resistance
5 – Full ROM against gravity full resistance without evident fatigue = Normal Muscle Strength
Normal individuals vary widely in their strength.
Remember to take into consideration Age, sex and muscular training.
If abnormality in ROM present- measure with a goniometer

23. Cerebellar Function Balance tests
Gait
Observe normal walk
Tandem Walking ( heel – to- toe )
Romberg Test (stand, feet together, arms at side, close eyes)
Shallow knee bend or hop on one leg
What findings would you expect to see when assessing gait and balance in an older adult?
Remember safety…. Stand close enough to prevent fall.
Rising from a sitting position without arm supports or stepping up on a sturdy stool rather than hopping for older patients

24. Cerebellar Function Coordination and Skilled Movements
RAM ( Rapid alternating movements)
Pat Knees
Thumb to each finger
Finger to finger
Finger to nose
Heel to shin

25. Question for Thought
List and describe 3 tests of cerebellar function?

26. Charting Sample For Normal Muscle Strength (objective)
Able to maintain flexion against resistance and without tenderness
For Motor ( objective)
No atrophy, weakness or tremors. Gait smooth and coordinated, able to tandem walk, negative Romberg. RAM, finger-to-nose smoothly intact