Reach, Grasp, and Manipulation

Question 1

What are the key components of UE control

Answer 1

1. Locate the object
2. transportation of arm in space
3. grasp/release
4. in hand manipulation

Question 2

Hand movements are more accurate if:

Answer 2

eye movements are involved

Question 3

during smooth pursuits there is an increase in gain if:

Answer 3

the hand also follows the target

Question 4

Kinematic studies of locating a target show

Answer 4

eyes reach object before head movement occurs

Question 5

EMG studies of locating a target show

Answer 5

neck muscles are activated first

Question 6

Control of movement: pointing

Answer 6

all segments of the arm are controlled as a unit

Question 7

Control of movement: reach and grasp

Answer 7

1. arm carries out transport phase
2. hand carries out grasp phase

each appears to be controlled by separate brain areas.

Question 8

grasping patterns vary depending on

Answer 8

1. location
2. size
3. shape of object
4. power vs precision

Question 9

what is the power grip

Answer 9

the finger and thumb pads are directed toward the palm and transmit force to the object

Question 10

when would you use a hook grasp

Answer 10

grabbing the handle of a suitcase

Question 11

when would you use a spherical grasp

Answer 11

holding a softball

Question 12

when would you use a cylindrical grasp

Answer 12

holding a bottle

Question 13

Precision grip

Answer 13

the forces are directed between the thumb and fingers

allows movement of the object relative to the hand and within the hand.

Question 14

Requirements for successful grasp

Answer 14

1. the hand must be adapted to the shape, size, and use of the object
2. the finger movements must be timed appropriately in relation to transport so that they close on the object just at the appropriate moment

Question 15

Shaping of the hand for grasp occurs during which phase?

Answer 15

transportation phase

Question 16

Shaping of the hand is affected by

Answer 16

1. the intrinsic properties of the object (size, shape, texture)
2. the extrinsic properties (orientation, distance from body, location)
3. size of max grip opening is proportional to size of object

Question 17

What are the 4 phases of grasp at lift tasks

Answer 17

1. contact between fingers and object
2. grip force and load force (load on fingers) increase
3. load force overcome weight of object (movement starts)
4. end of task

Question 18

what marks the end of grasp and lift tasks

Answer 18

decrease in grip and load force shortly after object makes contact with table

Question 19

role of cerebellum in grasp and lift tasks

Answer 19

predictive control of grip forces

Question 20

cerebellar lesion effect on grasp and lift tasks

Answer 20

poor predictive control of grip forces

Question 21

cortical lesion effect on grasp and lift tasks

Answer 21

normal timing of predictive grip forces but reduced amplitudes

Question 22

T/F: with a patient with coordiation dysfunction with reach and grasp, you need to train separately and together

Answer 22

True

Question 23

Changes in reach/grasp:

Hierarchical theory

Answer 23

reflexes provide physiological substrate for reaching.

The transition from reflex to voluntary behaviors is a gradual process

Question 24

development of reaching:

4-5 months

Answer 24

more accurate reaching and grasp components

Question 25

development of reaching:

9-13 months

Answer 25

pincer

Question 26

development of reaching:

12 months

Answer 26

higher cognitive aspects

Question 27

T/F: smooth pursuit develops before control of saccadic eye movement

Answer 27

False

Question 28

Initial tracking is performed with:

Answer 28

saccadic eye movements

Question 29

when do you see quick improvements in smooth pursuit

Answer 29

6 weeks of age

Question 30

eye/head coordination:

3 months

Answer 30

eyes stay on object most of the time

Question 31

eye/head coordination:

5 months

Answer 31

predictive abilities

Question 32

When are head movemenets seen in smooth pursuits

Answer 32

1 month olds and increases with ages through at least 5

Question 33

eye/hand coordination:

2 months

Answer 33

head-arm movements become coupled very strongly and then become uncoupled to allow more

Question 34

eye hand/coordination:

4 months

Answer 34

beginning postural stability

stable base for moving

Question 35

motor components of reach and grasp:

0-2 months

Answer 35

1. extension of arm
2. opening of hand
3. difficulty to grasp object

Question 36

motor components of reach and grasp:

4 months

Answer 36

1. reaching becomes more refined
2. approach path straightens
3. number of segments of reach decreases

Question 37

motor components of reach and grasp:

5 months

Answer 37

visually guided reaching

Question 38

motor components of reach and grasp:

reaction time

Answer 38

reduces with age up to 16-17 years

Question 39

how much does discrete reaching slow in velocity with age?

Answer 39

30-90%

Question 40

why does discrete reaching slow with age?

Answer 40

changes in information processing

Question 41

by age 70 time required to manipulate small objects

Answer 41

increases by 25-40%