Locomotion

Question 1

development trends of upright locomotion

Answer 1

• transition from flexor to extensor dominated limb action for load bearing and propulsion
• transitions from early locomotion to walking and running involve decreases in the size of the base of support with increasingly higher levels of the body’s center of gravity (mechanically, sway control is harder)
• higher levels of center of gravity and/or decreases in support base demand more developed balance control and therefore are accomplished first in a stationary position
• adding movement to these stationary positions requires a change from bilateral to alternate limb action, which in turn requires greater muscle strength and bone mass to support the boy unilaterally
• control is established in a cephalocaudal progression

Question 2

milestones (pre walking and walking)

Answer 2

roles over, crawling/creeping, cruising, walks alone

Question 3

rolling over (back to stomach)

Answer 3

usually not until close to 6 months of age, first true locomotion
- back to stomach

Question 4

pre walking progression (creeping, crawling)

Answer 4

• army crawl, hands and feet, all 4’s
• a lot of infants are skipping pre walking progression
• not absolutely necessary but helpful in the development of: gross motor skills, fine motor skills, hand eye coordination, balance, alternate limb movement

Question 5

early walking

Answer 5

mechanical patterns suggest that balance control is a huge problem
- arms up to catch the fall
- wide base
- short stride
- maintains stability

Question 6

differences in infant walking vs. adult walking

Answer 6

• step length: short
• step width: wide
• angle of feet: toes out
• pressure points: flat foot
• path traveled: wobbly, all over the place

Question 7

walking at 18 months..

Answer 7

toes no longer angled out

Question 8

walking at 2 years..

Answer 8

rocker action of the foot for weight transfer

Question 9

walking at 4 years..

Answer 9

adult-style walking including automatic arm swing

Question 10

differences in early walkers vs. adult walkers

Answer 10

• stride length: longer in adult
• hip movement: stays in same plane in adult because of heel/toe walk
• landing and push off surface: flat foot in infant
• hesitant action involving knee flexion just prior to propulsion, which results in exaggerated vertical lift during propulsion phase and resultant “falling” into each step

Question 11

late walkers

Answer 11

• with all movements and milestones, there is a large range of ages during which acquisition of skills are appropriate/typical
• infants who are not walking independently by 17-18 months should be examined clinically
  — usually late walkers also reached other milestones later than typical
  — delay possibly due to hypotonia: move frequent, reduced muscle tone
  — most late walking is idiopathic: can’t identify the cause

Question 12

requirements for successful locomotion

Answer 12

• strength
• stability: wide base, short stride
• progression
• adaptation: sway control

Question 13

responses to bursts of acceleration on the treadmill

Answer 13

• 2.5 to 4 years of age: nervous system attempting to control slip not with a reflex, but with later responses that can be generated by higher levels of the nervous system
• 4 years of age: starting to look more adultlike

Question 14

major milestones in grasp manipulation

Answer 14

• 4 to 5 months: picks up cube
• 8 months: picks up cube with complete thumb opposition
• 9 to 10 months: pincer grasp (thumb can hold small object between it and finger)

Question 15

development of manual control

Answer 15

• differentiating reach from grasp - initially simultaneous
• improving spatial accuracy of reach
• grasp location
• release
• force coordination for lifting and transporting
• grasp aperture control

Question 16

differentiating reach from grasp (declining dominance of flexor and extensor synergies)

Answer 16

• initially the hand opens when the arm is extended and closes when the arm is flexed
• around 2 months, fingers can flex during arm extension
• complete separation of reach and grasp by 4-5 months
• similar uncoupling of head/arm synergies by 4 months

Question 17

improving spatial accuracy of reach

Answer 17

• newborns reach but seldom contact; don’t use visual guidance during the movement and they don’t pre shape the hand for the object’s size and shape (visually triggered reaching)
• 3 months: reaches for stationary objects are 40% successful
• 4 to 5 months: 100% successful reaches and can intercept slowly moving objects

Question 18

improving spatial accuracy of reach cont.

Answer 18

• 6 months: adult like trajectories, but control of distance still developing
• 7 months: feedforward control (make plan for the reach) strategy is used for distance commands
• 7 years: feedforward strategy is combined with sensory information for mid course corrections of distance
• 9 years: feedforward and feedback strategies are combined for efficient and effective reaches

Question 19

grasp location

Answer 19

• objects grasped with palmar and ulnar hand early
• progresses to distal-radial locations as thumb opposition develops

Question 20

release

Answer 20

• 8 months: crude, able to put objects down
• 12-14 months: functional (can build tower of blocks 2 high)
• 18 months: controlled

Question 21

grasp aperture control

Answer 21

• little aperture (how much hand is open) control before 9 months
• 9 months: beginning of aperture control
• 7 years: vision used to set aperture, determining size and how open hand needs to be
• 12 years: aperture control used even when the object can’t be seen during the reach phase

Question 22

fundamental movements

Answer 22

~ 2 years

Question 23

there is a greater variability in development of fundamental skills because..

Answer 23

learning plays a greater role than maturation, no guarantee of reaching a mature state

Question 24

as fundamental movements begin to appear..

Answer 24

• many characteristics of the initial and elementary stages are consistent with the child preserving stability
• restricts motion (trying not to fall)
• maintains center of mass over base
• limits momentum

Question 25

running fundamental movement

Answer 25

• initial: short strides, upright posture, legs may cross over center line
• elementary: arm movements are forming
• mature: long strides, arms shouldn’t cross midline

Question 26

jumping fundamental movement

Answer 26

• initial: little arm movement, body upright, distance small
• elementary: arm movement, body thrust out to get momentum

Question 27

throwing fundamental movement

Answer 27

• initial: elbow movement only, follow through down, no lower body movement
• elementary: leg and arm move on the same side, step and throw on the same side
• mature: contralateral arm/leg movements, trunk rotation, wind up and follow through

Question 28

movements beginning to appear ..

Answer 28

• initial stages of most skills are marked by evidence of incoordination or failure to implement mechanically optimal patterns
• upper and lower limb components of a skill may be at different stages of development (different rates of maturity)

Question 29

movements are mature when..

Answer 29

less than 3 faults (characteristics of a movement that persists)

Question 30

what are the last fundamental movements to develop?

Answer 30

coincident timing skills

Question 31

coincident timing fundamental movements

Answer 31

• movements that involve intercepting or avoiding moving objects
• develop slower than fundamental skills that don’t involve coincident timing
• require maturation of visual perception skills, which typically don’t mature until ages 7-12 years or later (catching a ball)

Question 32

visual perception

Answer 32

brain assigning meaning to visual sensory signals
- involves experience with appropriate visual stimuli
- involves practice with the corresponding motor responses

Question 33

catching fundamental movement

Answer 33

• initial: no movement, hope to catch the ball
• elementary: no body movement, hands close after object reaches body
• mature: appropriate stance, catch ball, athletic stand