Typical Development: 18 Months - 6 Years Flashcards
In order to develop gross motor skills, what does a child need to be able to do?
- Balance with significantly reduced stability limits
- Maintain anti-gravity strength
- Steadily increase coordination between muscle groups
- Utilise intact sensory systems & cognition
- Anticipatory postural control improves instead of reactive
Which develops first, anti-gravity strength or independent stance?
Anti-gravity strength develops well before independent stance
Why is static balance more difficult for 2-6 year olds than adults?
Due to relatively high centre of mass (T12 vs L5)
How does experience influence the probability of effective postural responses occurring?
- Due to stronger connections between sensory & motor pathways
- Visual & somatosensory input remain essential for postural control throughout development
What drives development?
- Experience i.e. exposure to activities & practice (not maturation of the neural system alone)
- More efficient movement achieved with feed forward & feedback loops
What is age-related gait development due to?
- Increasing extensor muscle strength to support the body’s weight on a single limb BOS
- Development of dynamic balance with decreasing co-contractions for stability
- Improved postural control (anticipatory and integrative postural adjustments)
- Biomechanical changes
What are the characteristics of gait at ages 9-15 months?
- Wide BOS with abducted hips
- Slight hip/knee flexion & hip ER
- Lateral stability greater then AP
- Loses balance if head moves outside BOS
- Arms in high guard position
- Short stride
- Increased cadence
- Full foot initial contact
- Relative foot drop in swing phase
- Significant co-contraction
What does early walking resemble & what is it thought to be related to?
- Treadmill training (response to the momentum to keep balance)
- Thought to be related to stepping & kicking patterns in the newborn
What is an example of significant co-contraction during gait for 9-15 month year olds?
Tib ant & gastrocs co-contract during swing, quads & hamstrings co-contract during stance for stability
What are the characteristics of gait at ages 18-24 months?
- BOS decreases, now in line with pelvis
- COM descends
- Hip extension strength increases with mild hip extension during end of stance phase
- SLS becomes more stable
- Consistent heel strike with knee extension develops by 24months
- Increased velocity associated with increased stride length
- Decreased co-contraction due to improved control and stability
- Arms no longer in high guard
What is increased stride length correlated with?
Age, leg length and height
What are the characteristics of gait at ages 3-4 years?
- COM continues to descend
- Heel strike present with knee flexion in early stance
- Walking velocity normalised for height is now equivalent to adult
- Cadence decreases
- Reciprocal arm swing developing (firmly established by 4 years)
What are the characteristics of gait at ages 6-7 years?
- Gait generally fully matured
- COM still slightly higher (L3) than adult
- Cadence continues to decrease
- Balance & postural control show improvement
Why is there a period of disequilibrium between balance & postural control seen between 4-6 years?
Due to disproportionate growth compared to body dimensions
What are the main gross (fundamental) motor skills?
- Running, jumping, hopping, leaping
- Galloping, skipping, sliding
- Ball skills (catching, throwing, kicking, striking)
- Refer to checklists
What does postural control require?
Interaction of neural sensory (visual, vestibular, proprioceptive & tactile), motor & musculoskeletal systems
How does postural control change with development?
- More reactive in early stages
- Becomes more anticipatory (adaptive) with development
What does anticipatory postural control act to minimise?
Potential disturbance that may arise from initiating & completing a movement
