Cardioballistic impulse and fluctuations in isometric force output

Area of Science:

• Physiology
• Motor Control
• Biomedical Engineering

Background:

• Continuous isometric force production is essential for many motor tasks.
• Fluctuations in force output are influenced by various physiological factors.
• Cardioballistic impulse, reflecting blood pressure oscillations, is a potential modulator of motor control.

Purpose of the Study:

• To investigate the relationship between cardioballistic impulse and fluctuations in continuous isometric force production.
• To determine how visual feedback affects the coupling between blood pressure oscillations and force output.
• To examine the influence of force magnitude on this interaction.

Main Methods:

• Isometric force production using index finger flexion at 0.5, 1, and 2 N targets.
• Beat-to-beat blood pressure measurement of the middle finger.
• Quantification of force fluctuations using distributional statistics and coherence analysis.

Main Results:

• Force variability increased with higher force levels and absence of visual feedback.
• Significant coherence between blood pressure oscillations and force fluctuations was observed, particularly in the 8-12 Hz bandwidth.
• The coupling strength between blood pressure oscillations and force production was not affected by force magnitude but was greater with visual feedback.

Conclusions:

• Peripheral blood pressure alterations are linked to isometric force production fluctuations, irrespective of force level.
• Visual feedback plays a crucial role in modulating the interaction between blood pressure oscillations and force control.
• These findings contribute to understanding the physiological underpinnings of motor variability.