Intersegmental dynamics shape joint coordination during catching in typically developing children but not in children...

Area of Science:

• Motor Control
• Developmental Neuroscience
• Biomechanics

Background:

• Joint coordination is crucial for successful multijoint movements.
• Understanding developmental differences in motor control is essential for identifying learning disabilities.

Purpose of the Study:

• To investigate the factors shaping joint coordination during multijoint movements in typically developing (TD) children and children with developmental coordination disorder (DCD).
• To compare the movement strategies employed during a ball-catching task between TD boys and boys with DCD.

Main Methods:

• A one-handed ball-catching task was used with TD boys and boys with DCD aged 9-12 years.
• Kinematic data of shoulder, elbow, and wrist movements were analyzed.
• Coordination patterns and the utilization of interaction torque (IT) were compared between groups.

Main Results:

• Children with DCD had a substantially lower catching success rate compared to TD children.
• While joint motion amplitudes and directions were similar, coordination patterns differed significantly.
• TD children utilized sequential joint acceleration and passive IT, whereas DCD children simultaneously accelerated joints, suppressing IT.

Conclusions:

• TD joint coordination appears to minimize active control of IT, leveraging movement dynamics.
• Inefficient IT control in DCD suggests a deficiency in the internal model of intersegmental dynamics.
• Multijoint coordination may be a byproduct of control strategies that exploit movement dynamics, potentially reducing control-dependent noise.