topic 6

Question 1

posture
postural control
infant stance

Answer 1

• position adopted by parts of the body
• ability to detect changes in center of gravity in relation to base of support: necessary for stability (which is greatest when center of gravity passes through center of base of support)
• bigger base of support to stand because head is big-slight forward lean to balance weight-head=biggest rate limiter for stability

Question 2

development of postural control

Answer 2

1. minimal control-can hold head for a few seconds in prone (1 mo)
2. moderate control-can hold head and chin steadily up (2 mo)
3. full control-head and chest off ground using arm in prone (3 mo)
4. maximum control-can elevate in supine by lifting head (5 mo)

Question 3

rolling

Answer 3

• earliest pattern of voluntary locomotion
• requires postural control of head, neck, trunk
• enables child to obtain position for crawling/creeping
• head turns, followed by shoulders, trunk, hips
• sequence: 1. side to back (2 mo) 2. supine to side and prone to side (4 mo) 3. supine to prone (6 mo) 4. prone to supine (8 mo)
• affordances: toys (children roll towards them), rate limiters: postural control and strength

Question 4

sitting

Answer 4

-requires basic rolling ability and support reactions (i.e. parachute reflex)
-influences hand reaching (5-8mo)-non sitters less accurate and use 2 hands more often. all infants are more accurate sitting than supine
-sequence:
A. while supported, can sit w/ head steady (3-4 mo)
B. 1st attempts w/out support, forward lean (reflex stimulated to prevent falling)
C. unassisted, short time (5 mo), from prone/supine to sitting (8 mo), sitting down w/reasonable control (9 mo)

Question 5

standing

Answer 5

• standing w/assistance-7-8 mo (1st attempts being held under armpits)
• pushing/pulling to standing-9 mo-tables and chairs are affordances
• standing unassisted-12 mo

Question 6

crawling

Answer 6

• 1st effortful attempt at prone locomotion (6-8 mo)
• control of head, neck, and upper trunk required
• infant drags prone body with abdomen touching surface (precursor to creeping)

Question 7

creeping

Answer 7

-slow movement on hands and knees that infants will revert back to as a speedy form of locomotion
-homolateral movement=same arm/leg, occurs first
contralateral movement=opposite arm/leg

Question 8

origins of bipedalism

Answer 8

• endurance-greater stamina, more effective for tracking and killing prey
• increased thermoregulatory efficiency
• shift in diet (berry-picking)
• hands are freed (huge leaps in intelligence)

Question 9

walking

Answer 9

• continually losing and regaining balance while moving forward in a upright position
• independent walking achieved @ 10-15 mo (possible predictor is mm mass at 6 months-larger delays acquisition)
• mature pattern walking at 4-5 yrs

Question 10

early walking

Answer 10

• wide base of support
• flat-footed, toes turned out
• minimal ankle movement
• high guard position-limbs do not swing