Development of postural adaptation to arm raising.

Area of Science:

• Developmental motor control
• Biomechanics of posture
• Human movement analysis

Background:

• Postural control is crucial for stable movement.
• Understanding developmental changes in coordination is important.
• Arm movements significantly challenge postural stability.

Purpose of the Study:

• To investigate the development of postural-movement coordination.
• To analyze center of pressure (CoP) shifts during arm raising across different age groups.
• To examine the effects of load and age on postural adaptation.

Main Methods:

• Center of pressure (CoP) shifts were measured using a force platform.
• Arm movements were recorded using a TV-image processor.
• Participants (children aged 3-10 years and adults) performed arm raises with free or loaded hands.

Main Results:

• CoP shifted forward during arm raising, with greater shifts when hands were loaded.
• The relative amplitude of CoP shift decreased with age, with significant changes between 3-5 and 6-8 years.
• Anticipatory postural adjustments evolved from supporting to compensatory functions, improving stability recovery.

Conclusions:

• Significant developmental changes in postural adaptation occur between early childhood and pre-adolescence.
• Anticipatory postural adjustments become more sophisticated with age, integrating feedforward and feedback control.
• Older children and adults exhibit greater tolerance to unbalance during arm movements.