Lecture Six: Neurologic Impairments: Constraints on Motor Control

Question 1

Motor Cortex Pathology Deficits

Answer 1

• Motor paresis/paralysis
• Abnormal muscle tone
• Loss of selected muscle activation

Question 2

Paresis

Answer 2

Mild or partial loss of muscle control( weakness)

Question 3

Paralysis/-plegia

Answer 3

Total or severe loss of muscle activity

Question 4

Paresis/Paralysis

Answer 4

• Hallmark of UMN injury/lesion in descending motor system

- Prolonged paresis leads to secondary effect of muscle structure changes and further weakness

Question 5

Abnormal Muscle Tone

Answer 5

Muscle tone- “ stiffness” if muscle; resistance to passive stretch
- Flaccidity, Hypotonia, Normal, Hypertonia,Rigidity, Spasticity, Clonus

Question 6

Flaccidity

Answer 6

Lack of muscle tone

Question 7

Hypotonia

Answer 7

Low muscle tone

Question 8

Normal

Answer 8

that there is the right amount of “tension” inside the muscle at rest, and that the muscle is inherently able to contract on command.

Question 9

Hypertonia

Answer 9

abnormally increased resistance to externally imposed movement about a joint (increase resistance to passive stretch)

Question 10

Rigidity

Answer 10

increased muscle tone, means stiffness or inflexibility of the muscles. In rigidity, the muscle tone of an affected limb is always stiff and does not relax, sometimes resulting in a decreased range of motion.

Question 11

Spasticity

Answer 11

• Velocity dependent, moving the limb faster will show spasticity
• abnormal muscle tightness due to prolonged muscle contraction

Question 12

Clonus

Answer 12

muscular spasm involving repeated, often rhythmic, contractions.

Question 13

Loss of selected muscle activation

Answer 13

• Individual/ fractionation of movement
• Skilled, efficient movement
• Impaired Individual

Question 14

Individual/Fractionation of movement

Answer 14

ability to selectively activate a muscle for isolated joint motion

Question 15

Skilled, efficient movement

Answer 15

Activate only muscle necessary for the task

Question 16

Impaired Individual

Answer 16

Abnormal coupling of muscle= Abnormal synergies
- During voluntary movement, an attempt to activate one muscle results in activation of abnormal coupled muscles
- Stereotypical movement patterns that cannot be adapted to task/environment
- Strong linkages; movement outside of fixed pattern is minimal or not possible
Abnormal synergies result from increased recruitment of descending pathways from the brainstem

Question 17

Abnormal Synergies

Answer 17

UE Flexor Synergy Pattern

LE Extensor Synergy Pattern

Question 18

UE Flexor Synergy Pattern

Answer 18

Scapular retraction, shoulder abduction/ER, elbow flexion, forearm supination, wrist/ finger flexion

Question 19

LE Extensor Synergy Pattern

Answer 19

Hip Extension/adduction/IR,knee extension, ankle PF/inversion, toe flexion

Question 20

Loss of Selected Muscle Activation

Answer 20

Coactivation : Simultaneous activation of agonist/antagonist
Typical
Atypical

Question 21

Cerebellar Pathology Deficit

Answer 21

Hypotonia

Ataxia/Coordination problems

Question 22

Hypotonia

Answer 22

Reduction in stiffness to passive lengthen of a muscle
May be associated with cerebellar pathology ot other disorders
Children: development delay; Ex: Down Syndrome

Question 23

Normal Coordination

Answer 23

Synergistic nature of muscles working together to produce smooth movement

Question 24

Ataxia/Coordination Problems

Answer 24

Problems with smoothness, sequencing, timing, grading, and accuracy

Question 25

Smoothness

Answer 25

Movement happens in continual fashion without interruption in velocity or trajectory

Question 26

Sequencing

Answer 26

Specific order of motor output requires to achieve intended goal of the action

Question 27

Timing

Answer 27

Relative percentage of time devoted to movement segments ( initiation, execution and termination)

Question 28

Grading

Answer 28

Amount of force/range of movement used

• Hypometria: Undershooting; underestimation of force/range of movement
• Hypermetria: Overshooting; overestimation of force/range of movement

Question 29

Accuracy

Answer 29

Freedom from error

Question 30

Coordination

Answer 30

Discoordination issues

• Delayed reaction time
• Errors in range of movement and direction of movement( Dysmetria)
• Inability to sustain rhythmic movements (Dysdiadochokinesia)
• Difficulty terminating movements
• Difficulty changing direction of movement

Question 31

Examples of Coordination Test

Answer 31

• Finger to nose
• finger to therapist
• Alternate nose to finger
• Finger to opposition
• Rebound Test
• Tapping ( hand, foot)
• Heel on shin

Question 32

Basal Ganglia Pathology

Answer 32

Hypokinesia Ex: Parkinson

Hyperkinesia Ex: Huntington’s Chorea; athetoid cerebral palsy

Question 33

Hypokinesia

Answer 33

Diminished movement

• Bradykinesia
• Akinesia
• Rigidity

Question 34

Bradykinesia

Answer 34

Slowed execution time for movements

Question 35

Akinesia

Answer 35

Reduced ability to initiate movements

Question 36

Rigidity

Answer 36

Increase resistance to passive movement that is not velocity dependent

• Led pipe rigidity: constant resistance through entire ROM
• Cogwheel rigidity : alternating resistance- relaxation “ catches”)

Question 37

Hyperkinesia

Answer 37

Excessive and involuntary movements

• Chorea
• Athetosis

Question 38

Chorea

Answer 38

Involuntary, irregular, jerky movements

Question 39

Athetosis

Answer 39

Slow involuntary writhing and twisting movements

Question 40

Dystonia

Answer 40

Syndrome characterized by sustained muscle contractions with twisting & repetitive movements and abnormal postures

• Diverse movement patterns, range from slow athetotic to quick myoclonic
• often involves co- contraction agonist/antagonist

Question 41

Temporal Sequence Task Analysis

Answer 41

• Initial Conditions
• Preparations
• Initiations
• Executions
• Termination