Bounded stability of the quiet standing posture: an intermittent control model

Area of Science:

• Biomechanics
• Control Theory
• Human Motor Control

Background:

• Quiet standing involves complex postural control to maintain balance.
• Human balance relies on sensory feedback and internal predictive mechanisms.
• Existing models often struggle to replicate natural sway patterns accurately.

Purpose of the Study:

• To present a novel control model for body sway in quiet standing.
• To achieve bounded stability using an intermittent control mechanism.
• To explain measured sway patterns with a simple, robust model.

Main Methods:

• Developed a control model based on an intermittent control mechanism.
• Incorporated an internal model of human inverted pendulum biomechanics.
• Simulated control bursts triggered by state vector deviations from an uncertainty region.

Main Results:

• The model demonstrates bounded stability in quiet standing.
• It accurately explains detailed measured body sway patterns.
• The model shows robustness despite reliance on noisy proprioceptive signals.

Conclusions:

• An intermittent control model can effectively manage body sway.
• Predictive internal models, even simplified, are crucial for postural control.
• This approach offers a robust explanation for human balance dynamics.