Increased Speed Elicited More Automatized but Less Predictable Control in Cyclical Arm and Leg Movements.

Area of Science:

• Biomechanics
• Motor Control
• Human Movement Analysis

Background:

• Cyclical movements, such as walking and punching, are fundamental to human activity.
• Understanding the interplay between automaticity and predictability in these movements is crucial for various applications.
• Previous research has explored aspects of movement control, but a direct comparison of automaticity and predictability across different tasks and speeds is needed.

Purpose of the Study:

• To investigate how automaticity and predictability vary in cyclical arm and leg movements.
• To compare these variations between treadmill walking and a repetitive punching task.
• To examine the effect of different speeds on movement automaticity and predictability.

Main Methods:

• Twenty healthy adults participated in the study.
• Participants performed treadmill walking at three speeds: lower-than-preferred, preferred, and higher-than-preferred.
• A repetitive punching task was performed, cued by the walking frequencies, with arm, leg, and trunk movements digitized using inertial sensors.

Main Results:

• Treadmill walking exhibited smaller absolute slope values (|β|) in power spectrum analysis compared to punching, indicating greater automaticity.
• Sample entropy measures were larger during walking, suggesting reduced predictability compared to punching.
• Increased movement speeds in both tasks led to enhanced automatized control but decreased movement predictability.

Conclusions:

• Treadmill walking is more automated yet less predictable than repetitive punching.
• Higher movement speeds increase automaticity but decrease predictability in cyclical tasks.
• These findings have implications for evaluating task demand changes in clinical settings, particularly concerning movement control and adaptation.