reach and grasp Flashcards
new borns can track an abject using
saccadic eye movements
at birth and infant can move his attention from one object to another. as he matures, he goes through a period of obligatory looking, but is able to disengage from and object again by about
4 mo
limited smooth pursuit is present at birth and begins to improve at _____. infants track objects well by ________ and use the head and eyes together by _____
6 wks
3 mo
5 mo
head-arm movements are strongly coupled by
2 mo
infants gain trunk postural stability, providing a stable base for the emergence of reaching at
4 mo
moves arm when visually fixated on and object, open hand
newborn
frequincey of reaching decreases, hand fisted
2 mo
frequency of reaching increases, hand open, infants acquire skill in aiming movements and become realistic in their reaching
3 mo
reaching movements are _____
visually triggered
reaching occurs in several steps, bimanual reaching may dominate, elbow may be locked, final approach is crooked/awkward, reaching becomes visually guided
4-5 mo
reaching becomes smoother (fewere steps and straigener approach), unilateral reaching may begin, elbow is used
6 mo
coordinated/complementary bimanual reaching (transfers objects) controlled release
8-9 mo
reaching changes little from
9 mo to 7 years
use ballistic reaching strategies
5 yr old
constantly monitor and control their reaches witha closed loop strategy
7 yr old
children combine strategies to improve efficiency and reduce the mound of attention required
9-11 yr olds
reflexive grasp, hand is open during reaching
newborn to 2 mo
hand is fisted during reaching
2 mo
open hand when infant is visually fixated on target
3 mo
infants begin to use vision to correct hand trajectory, palmar grasp emerges
4-5 mo
infants expect to see hand and performance is disturbed if vision of hand is blocked; visual info is used to adjust grip configuration, radial palmar grasp
5-6 mo
opening of hand during reaching is related to size of object, pincer grasp emerges
8-9 mo
grasp is initiated earlier in the reach, timing is similar to adults, pincer grasp is well-developed
12-13 mo
grip and load force are negatively correlated, tendency to over-shoot target
2 yrs
children begin to use and anticipatory control strategy for grasp (grip and load force become positively correlated, less overshooting)
4 yrs
grip and load forces are programmed in parallel to prevent slips and avoid squeezing too hard, integration of feedback and feedforward stragies
adults
rotation of held objects
2 mo
translation of grasped objects
3 mo
vibration of held objects
4 mo
bilateral hold of 2 objects
2 handed hold of a single object
4.5 mo
find partially hidden objects, explores objects with hands and mouth
6-7 mo
object permamence and separation anxiety
8 mo
begins to use objects correctly, imitates gestures
12 mo
stacks 2 blocks, adapts reaching to the weight of the object
13-15 mo
stacks 3 blocks, understands objects go together
18 mo
stacks 6 blocks, sorts by shape/color, begins pretend play
2 yrs
completes puzzle with 3-4 peices
3 yrs
