Lecture looks at
the formation of goal oriented behaviors such as early reaching, bimanual coordination, and object manipulation.
Reflexes are involuntary responses to stimuli.
2 Several reflexes appear at birth
3 disappear with age
4 develop into gross motor skills
Motor-skills can be broken down into these two-categories:
1) Gross Motor Development
2) Fine Motor development
· refers to the control of objects in the spatial environment.
Importance of skills
Ø Provide another way in addition to seeing and hearing that infants can explore their environment
learn about their environment / new world
– A grasping reflex in newborns
and rudimentary form of reaching
- Decline at 2 months
- occurs at 3 months: more complex
and efficient pattern of reaching
- by 3 months
- 4 month olds rely more on touch
to determine grip configuration
- 5 months (in normal environment) infants
are able to reach in a directed way for an object and successfully grasp it.
- 6 months They can reach and
grab onto an object they are concentrating on.
- 8 month use vision as a guide
– more efficient as allows infant to preshape his hand as he reaches for the object
- Up to one year: infants become highly skilled
in exploring their world with their hands.
to two-handed reaching
· Despite that dramatic behavioral progression, many infants return to two-handed reaching near the end
of the lst year-- particularly when objects are presented at midline
· No one has been able to offer a plausible explanation as to why infants activate two arms again when
reaching for small objects toward the end of their 1st year.
effects of motor development of reaching and grasping
· enriching the visual world of deprived infants advanced their abilities to attend to objects and to
reach for them
Ø Hanging colorful toys over babies cribs
them with multicolored sheets
babies handled more often by their caretakers
Ø Experimental babies exhibited visually directed reaching by just over 3 months
faster than controls
When and how infants
begin to grasp objects of different sizes, and when object-specific grasping patterns emerge.
How infants grasp
· Infants vary their grip according to the size and shape of the object
· As well as the size of their own hands relative to the objects size
sequence of grasping
– 16 weeks begin to use the forearm
and the hand to reach with greater effectiveness
– 20 weeks the use of a crude palm grasp emerges.
– 16- to 24-weeks finger movements are very
crude, and the hand often reaches behind the object to grasp it.
– 28 weeks infants begin to use thumb-finger
– 36 weeks infant's approach becomes stable
– 40 weeks infants are able to extend the
index finger toward the object.
Ø Changes may be observed until the age of six years or later, when the features of adult grasping are established.
Children learn to
the forces on the basis of an internal model (motor memory and representations),
on vision for shaping the configuration of the hand when we are about to grasp an object.
hand receptors are also essential and come into play to update the memorized representations.
the (unconscious) use of the hands in adaptive corrections of the grip, the hands are, of course, used for conscious perception
of an object's properties (reaching to sense the immediate environment, a particularly important activity for normal development).
· The relationship of infant sleep and play positioning to motor milestone achievement.
Eg: Salls, Silverman,
· A cross-sectional sample of 66 infants
· Ages: 2.0 (n = 23), 4.1 (n = 26), and 6.0 (n = 17) months of age
· Caregivers identified infants' primary sleep positions and amount of awake-time in prone.
· The sample of 2.0-month-old supine and side sleeping infants differed significantly from the normative
population on three gross motor milestones.
· Two-month-old infants spending 15 min or fewer of awake-time in prone passed the gross motor milestones
at significantly lower percentages than the normative population.
· No significant differences were noted between sampled and normative populations at 4.1 and 6.0 months
· Results suggest that infant gross motor development may be related to sleep and play positioning.
One of the babies’
early achievements is the ability to reach, grasp and pick up objects
Second is ability
to reach things beyond their immediate grasp by:
· include movements that change the child from one location to another,
such as crawling,
o running, leaping,
jumping, hopping, skipping, galloping, rolling, and climbing
of development of locomotion:
1. Stepping Reflex
2. Reappearance of stepping reflex
3. walking without support
of motor-skills depends on…
· maturation and readiness
· all children develop physical skills in a predictable, observable sequence, there are definitely individual
Improvement of motor skills through practice:
· researchers held that motor behaviors emerged as a consequence of the interaction between the children's
maturation and experience.
· Theorists in the 1980s proposed that motor skills could be improved through practice, learning, and
· More recently, researchers have gathered evidence that appears to verify these theorists' position
that motor skills are improved through intervention
· Researchers have reported that children receiving targeted motor intervention programs that promote
the identified sequential skills make significant gains in motor development
Eg: Can infants
between the ages of 2 months and 12 months step as long s they’re given stability and postural support necessary to
stretch each leg forward and back while in an upright position?
and Thelen and Smith (1994)
· Held 7 month olds on a motorized treadmill
· Immediately they performed alternating stepping movements that were remarkably similar to more mature walking
· Were able to adjust walking speed when the treadmill moved at different rates for each leg.
Ø E.g. Zelazo et al (1972)
mothers of newborns to give their infants practice in the stepping reflex a few minutes a day
to 8 week old infants made more walking responses and walked independently at an earlier age than a control group who were
given no practice.
practice in sitting yielded similar results
is highly specific: so practice in stepping does not affect sitting
of other locomotion
· Running well established by the time the child is a year and a half years old
· Galloping emerges at the same time
· These skills depend on
Ø improvements in balance
Locomotion and other
aspects of development
· development changes in one domain have important implications for changes in another.
Ø E.g.: blindness retards motor development considerably
- being blind lessens the infants ability
to explore independently
· Locomotion affects the way babies understand their perceptual world
Ø E.g. babies develop a fear of heights only after they begin crawling
locomotion and the role of culture
of rearing customs on motor patterns
studies have provided some insights on how specific ways of caring for newborns and infants can alter motor patterns.
· Two related factors that may stimulate children’s early motor development that differ among cultures are:
1) physically handling infants
2) giving them exercise in various motor skills
and the elderly
· Changes in gait
· Falls are a major contributor to the increasing morbidity rates seen in the older population.