Motor Systems Components

Question 1

What are some primary neuromusclar impairments that can result from a neurological pathology?

Answer 1

1. Muscle weakness
2. Abnormal tone
3. Coordination deficits
4. involuntary movements

Question 2

What are some secondary neuromusclar impairments that can result from a neurological pathology like an UMN lesion?

Answer 2

1. ROM and alignment issues
2. Endurance issues
3. Pain

Question 3

how would you define muscle weakness as a neuromusclar impairment?

Answer 3

inability to generate force or recruit/modulate motor units

Question 4

list some neural contributions that can result in the primary neuromusclar impairment of muscle weakness

Answer 4

Change in:

1. # of motor units recruited
2. D/C frequency
3. type of motor unit recruited

Question 5

What are some potential neurological pathologies that can result in neuromusclar weakness as an impairment?

Answer 5

1. Cortical lesions
2. lesions in descending pathways
3. disruption of impulses to alpha motor neurons
4. peripheral nerve injury
5. synaptic dysfunction at NMJ

Question 6

Muscle weakness as a neurological impairment can result in what secondary impairments/observations?

Answer 6

1. postural abnormalities
2. asymmetrical weight bearing
3. abnormal synergies

Question 7

list 2 types of abnormal synergies

Answer 7

1. Flexor synergy (UE)
2. Extensor synergy (LE)

Question 8

describe a flexory synergy?

Answer 8

scapular retraction and elevation

shoulder abduction and ER

elbow flexion

supination

wrist and finger flexion

Question 9

describe an extensor synergy

Answer 9

hip extension, adduction and IR

knee extension

ankle PF and inversion

toe PF

Question 10

what is tone?

Answer 10

muscles’ resistance to passive stretch

Question 11

Describe the continuum/varying levels of tone

Answer 11

From too little to too much

1. Flaccid
2. Hypotonicity
3. normal
4. hypertonic/spasticity
5. Rigid

Question 13

what are the neural contributions to normal tone?

Answer 13

net balance of descending input on motor neurons from:

corticospinal tracts

rubrospinal tracts

reticulospinal tracts

vestibulospinal tracts

as well as the sensitivity of synaptic connections

Question 14

what are the non neural contributions to normal tone?

Answer 14

1. CT plasticity
2. viscoelastic properties of the muscles, tendons, and joints

Question 15

How is spasticity different from hypertonia?

Answer 15

spasticity is velocity dependent and hypertonia is not

Question 16

Spasticity can sometime be described as a ___________

Answer 16

clasp-knife phenomenon

Question 17

what is a typical cause of spasticity and a common result/association?

Answer 17

damage to pyramidal tract or other nearby descending paths

can be associated with clonus (commonly in distal > proximal extremities)

Question 18

Describe the mechanism by which spasticity occurs

Answer 18

1. changes in neural contributions
2. results in decreased descending activity
3. reduction of inhibitory synaptic input
4. increases tonic excitatory input
5. results in alterations to threshold of stretch reflex

Question 19

List 2 scales typically used to measure tone

Answer 19

1. Modified Ashworth Scale
2. Tardieu scale

Question 20

which scale used to measure tone, also gives us info on spasticity?

Answer 20

Tardieau

since we vary the velocities (V1, 2, 3)

Question 21

which applied velocities equate to spasticity on the Tardieau scale?

Answer 21

V2 = speed of limb falling under gravity

V3 = fast as possible

Question 22

In what muscle group is hypertonia typically observed?

Answer 22

Flexors

Question 23

When testing hypertonia with movements, it can be described as _________ or _________

Answer 23

leadpipe or cogwheel

Question 24

what is the difference between leadpipe and cogwheel hypertonia?

Answer 24

leadpipe = constant resistance to movements throughotu entire ROM

Cogwheel = alternating episodes of resistance and relaxation

Question 25

what is hypertonia at rest called?

Answer 25

Posturing

Question 26

What are the 2 types of posturing?

Answer 26

decorticate = UE flexion, LE extension/IR/PF decerebrate = UE and LE extension

Question 27

what type of posturing is due to a lesion at or above the level of the red nucleus?

Answer 27

decorticate posturing

Question 28

characteristic of the tone abnormality depends on what factors?

Answer 28

1. type and location of pathology 2. Chronicity * increases in nonneural changes = increased "stiffness"

Question 29

List the type of abnormal tone that would result if a lesion occured at the cortical, brainstem, and basal ganglia level?

Answer 29

1. cortical: pyramidal → change in descending inputs of alpha motor neurons → spasticity 2. Basal ganglia: extra pyramidal → rigidity 3. brainstem: above/below red nucleus → decorticate/decerebrate posturing

Question 30

List some pathologies in which hypertonicity is commonly observed

Answer 30

1. CVA 2. TBI 3. MS 4. Parkinsons Disease (rigidity)

Question 31

define hypotonicity

Answer 31

reduction in resistance to lengthening reduction in "stiffness"

Question 32

hypotonicity can be described as _______ or \_\_\_\_\_\_\_

Answer 32

floppy = collapse into gravity, harder to excite flaccidity = complete loss of muscle tone

Question 33

what causes hypotonicity?

Answer 33

disruption of afferent input from stretch reflex → lack of cerebellar efference influence → result in decreased input to gamma motor neurons

Question 34

List some pathologies where hypotonicity is commonly observed

Answer 34

1. Cerebellar lesions 2. down syndrome 3. musclar dystrophies 4. late stage ALS 5. post-polio 6. Acute CNS injuries → typically end up resulting in hypertonicity/spasticity once subactue phase is over

Question 35

what are the functional implications for increased tone?

Answer 35

1. abnormal posturing 2. misalignment 3. high risk for injury during prolonged rest (skin breakdown) 4. bias with recruitment 1. increased likelihood of synergistic movement 5. destabilization with changes in position (clonus, increased risk for contractures)

Question 36

what are the functional implications for decreased tone?

Answer 36

1. fall into gravity 2. high risk for injury during dynamic tasks

Question 37

define coordination

Answer 37

ability to use parts of the body together smoothly and efficiently

Question 38

what are the critical components of coordination?

Answer 38

1. sequencing 2. timing 3. grading

Question 39

define incoordination

Answer 39

movements that are awkward, uneven, inaccurate disrupting of sequencing, timing and grading loss of coupling between synergistic joints and muscles

Question 40

incoordination is typically observed with what types of lesions?

Answer 40

motor cortex basal ganglia cerebellar (proprioceptive lesions too)

Question 41

the functional implications of incoordination can be divided into what categories?

Answer 41

1. grading/scaling dysfunction 2. timing difficulties 3. activation and sequencing problems

Question 42

what are the types of grading/scaling dysfunctions found with incoordination?

Answer 42

1. dysmetria = under/overshooting intended position (a type of ataxia) 2. hypermetria = moving beyond intended goal 3. hypometria = moving short of intended goal

Question 43

list some timing difficulties that are a result of incoordination

Answer 43

1. increased reaction times 2. slowed movement times 3. difficulty terminating movements 4. rebound phenomenon 5. dysdiadochokinesia

Question 44

list some activation and sequencing problems that occur with incoordination

Answer 44

1. abnormal synergies 2. coactivation 3. impaired inter-joint coordination

Question 45

what are the components of the coordination examination?

Answer 45

1. finger to nose 2. alternating pronation/supination 3. hand or foot tapping 4. heel to shin

Question 46

List several categories/types of involuntary movements that are primary neuromusclar impairments

Answer 46

1. dystonia 2. tremors 3. choreiform 4. athetosis

Question 47

what is dystonia?

Answer 47

syndrome dominated by sustained muscle contractions causing twisting, repetitive movements, and abnormal postures

Question 48

what region of the brain is dystonia correlated with?

Answer 48

basal ganglia

Question 49

what are tremors?

Answer 49

rhythmic, involuntary oscillatory movement of a body part can be intermittent or constant, sporadic or as a sequale to a disease or injury

Question 50

what is the difference between a resting and active tremor?

Answer 50

resting = occurs in a body part that is not voluntarily activated (it's relaxed) active = any tremor produced by voluntary contraction of muscle (can be postural or intention)

Question 51

what is a postural tremor? Intention tremor?

Answer 51

postural = person maintains a part of body against gravity intention = produced with purposeful movement

Question 52

what is a choreiform?

Answer 52

involuntary, rapid, irregular and jerky movements seen with Huntingtons disease and is a SE of PD meds

Question 53

what is athetosis?

Answer 53

slow, writhing and twisting movements UE \> LE common in CP

Question 54

What causes endurance issues to be a secondary neuromuscular impairment?

Answer 54

1. decrease in central drive to spinal cord motor neurons 2. decrease in activity level/immobility