Main content
MCAT
Course: MCAT > Unit 11
Lesson 2: Human development- Human physiological development
- Egg, sperm, and fertilization
- Early embryogenesis - Cleavage, blastulation, gastrulation, and neurulation
- Implantation
- Germ layer derivatives
- Gestation
- Major motor milestones
- Motor development
- Neonatal reflexes
- Physical development in adolescence
- Brain changes during adolescence
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Motor development
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Want to join the conversation?
- how can u describe motor development in adolescent(3 votes)
- What do you mean when you say that muscles "develop"?
Do new muscles form as a child matures?
Or are children born with all of their muscles and more myocytes form as they mature (just like more myocytes form as an adult works out)?
Or are the sensory/motor neural connections weak? (How do you strengthen a neural connection, anyhow?)(2 votes)
Video transcript
- [Instructor] I want to
talk about motor development as it relates to the
nature-nurture debate. And the nature part of this debate is spoken about in terms of maturation. Which refers to genetic
factors as well as anatomical and neurophysiological traits
that drive motor development. And we know that motor skills are driven by internal biological factors
for a number of reasons. For example, we know that identical twins typically begin to walk on the same day. Much closer than non-related
infants of the same age. Other evidence for this
is the fact that children all over the world tend to develop skills at the same time and in the same order. We also know that blind
children tend to show the same timing and progression, and they obviously could
not have learned this through observation and
imitation of those around them. And this actually makes a lot of sense when you think about it. As children grow, their
brains and their muscles grow as well. And before areas of the brain
like the cerebellum develop and before the muscles are strong enough, infants simply aren't developed enough to allow for things like
crawling or walking. They can't sit up or crawl or walk without that biological support. No matter how much practice or experience a parent tries to give. And I want to point out
that the same is true for the muscles involved
in bladder control and bowel control. Toilet training simply can't happen before those muscles are developed. It doesn't matter what
rewards or punishments parents try to give. But the environment can
still play an important role in the development and motor skills. How much space and time a child
has to practice these skills can have an affect on development. Culture can also have an
influence on development. For example, these days
doctors typically recommend that infants sleep on their backs instead of on their stomachs. And this is great advice. That small change in how children sleep significantly decreased the chances of sudden infant death syndrome or SIDS. However, we also now know
that the sleeping position tends to be correlated
with children crawling at a somewhat later time. And of course, this really doesn't matter in the scheme of things. And sleeping position doesn't affect the development of later
motor skills, like walking. But it is an interesting way
that our culture winds up influencing motor development. We also know that wearing diapers can lead to children
walking slightly later. But to me, this seems
like a small price to pay for the convenience. I suppose you could follow
your child around all the time or maybe cover your
entire home in plastic, but that sounds like a lot more
work for not a lot of gain. There are also a couple of
patterns that you should keep in mind when you think
about motor development. The first one is that we can
break motor skills down into two main types: gross motor
skills and fine motor skills. Gross motor skills are skills
that involve larger muscles, our arms and our legs. While fine motor skills refer to movements that involve smaller
muscles, like our fingers. So gross motor skills would involve things like sitting up and walking. While fine motor skills
would be things like cutting with scissors
or coloring a picture. And as you might expect, large muscles like those
in our arms and legs tend to develop before small muscles like the ones in our fingers. Which explains why we can do
things like sit up and walk before we can hold a
marker and color a picture. Development also tends to move
from the head to the toes, which is why babies are
able to lift their heads before they can crawl. And maybe you're a parent, and you're wondering if there is anything that you can do to speed
up these motor milestones. And the answer is, kind of. As we mentioned earlier, certain actions can't physically be done until the brain and the muscles are ready for them. But, once that child starts a behavior, it is good to provide
a lot of space and time that will allow the child to practice. Also, enriched environments
with different kinds of toys can allow for increased motor exploration, which seems to speed up the rate at which certain milestones might be achieved. That said, I do want to stress
that the research indicates that it doesn't necessarily matter and that children who are
late in developing some skills might be faster in attaining others. And I also want to take
a moment to point out, any parents who may be watching this, that they might want
to appreciate the time before their children
develop motor milestones rather than trying to speed them up. Because once children
start moving independently, they don't really ever stop. So enjoy the time that you have when you can put an infant
down and look away for a moment while still being confident
that the child will be in the same spot when
you turn back around.