Variation between individuals in sensorimotor feedback control of standing balance

Area of Science:

• Human motor control
• Sensorimotor neuroscience
• Biomechanical modeling

Background:

• Intersubject variation in human balance is significant.
• Sensorimotor feedback mechanisms are crucial for maintaining balance.
• Understanding individual differences in balance control is important for various applications.

Purpose of the Study:

• To investigate intersubject variation in human balance control.
• To determine if differences in central sensorimotor processing explain variations in balance.
• To examine if similar sensorimotor feedback mechanisms are employed for sagittal and frontal balance.

Main Methods:

• Twenty-one adults stood on a rotating platform with eyes closed.
• A model incorporating plant dynamics and feedback control parameters was used.
• Postural sway metrics (RMS sway, RMS velocity) were analyzed.

Main Results:

• Intersubject variation in balance characteristics was linked to central sensorimotor processing.
• Sensory weight and integral gain showed moderate to strong correlations between sagittal and frontal planes.
• Central feedback mechanisms, rather than plant dynamics, better predicted sway variations.

Conclusions:

• Intersubject variation in balance arises from differences in central sensorimotor processing.
• Sensorimotor feedback mechanisms are partially conserved between sagittal and frontal balance.
• Individual differences in sensory weighting, time delays, and motor scaling significantly impact postural sway.