Chapter 23. Sequence of Motor Development

Learning Objectives

cortex

outermost layers on the surface of the brain, where most cognitive processing occurs

maturation

process of growth and development guided by an individual’s genetic plan

dendrites

the part of a neuron specialized for receiving signals from other neurons; dendrites often resemble the branches of a tree

neuron

a single nerve cell, forming the basic unit of the nervous system

Sequence of Motor Development

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Learning Objective:

Describe the typical stages of motor development between birth and one year.

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1. As an infant’s brain develops, the infant gradually gains control over his or her muscles. This allows the infant to interact with people and objects and move around to explore the environment.

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The figure is a time line from 0 to 12 months. Over the time line are images of an infant as it progresses from laying on its stomach at 0 months to walking at 12 months. Important milestones on the time line include rolling over at 5 months, sitting up at 6 months, standing up at 8 months, crawling at 9 months, and walking around 12 months

2. This process is mainly driven by maturation, and occurs in the same basic sequence in infants around the world. The sequence is called the motor development milestones.

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3. After the first month, infants can control their neck muscles and can lift their heads. By 4 to 5 months of age, most infants can roll over.

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4. On average, infants can sit up with support by age 5 months. They can sit without assistance by 6 months of age.

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5. Over the next few months, infants become mobile, first by slithering across the floor and then by crawling on their hands and knees.

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6. By 9 or 10 months old, most infants can pull themselves up into a standing position and perhaps "cruise" along a piece of furniture by holding on to it for support.

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7. About 50 percent of infants can walk alone by 12 months of age, and 90 percent can walk well by age 15 months.

23.1 Practice: Observing the Motor Milestones

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Practice: Observing the Motor Milestones

Play the video. Then select the CONTINUE button to observe another motor milestone.

Lift Head

On average, infants can lift their head by about 2 months old. This motor milestone occurs early, often in combination with the reflexive movements of the arms and legs that are observed when infants lie on their stomach.

asset/activities/motor_development/video/32Vid-01.mp4

NOTE: this video has no audio.

Quiz 1

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Quiz 1

Drag each image to a numbered location to arrange the stages of motor development in the appropriate sequence. When all the images have been placed, select the CHECK ANSWER button.

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The first infant is standing at a table with hands on the table top

The second infant is laying on its back and rolling to the side

The third infant is walking with outstretched arms

The fourth infant is sitting on the ground

Quiz 2

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Quiz 2

After you play the video, select the best option to answer the question. Then select the CHECK ANSWER button.

asset/activities/motor_development/video/32Vid-05.mp4

Select the NEXT button and move to the Conclusion.

Try to answer the question again.

The video clip illustrates which stage of motor development?

cruising

standing

walking

Conclusion

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Congratulations!

You have completed the activity Sequence of Motor Development.