Aging and the mechanisms underlying head and postural control during voluntary motion

Area of Science:

• Gerontology
• Neuroscience
• Biomechanics

Background:

• Head stability is critical for balance and sensory information processing during body movement.
• The coordination of head and body motion for balance in older adults during volitional activities remains understudied.

Purpose of the Study:

• To establish a framework for understanding how aging affects head control during voluntary motion.
• To present data illustrating how elderly individuals may control head movement to enhance gaze and vestibular input quality.

Main Methods:

• Proposed a "top-down" or "head-first" control scheme for head stabilization in non-disabled elderly individuals.
• Introduced the head-stabilization-in-space (HSS) strategy, which maintains constant head angular position irrespective of body's center of force displacements.
• Discussed the roles of geocentric, egocentric, and exocentric frames of reference in refining head stabilization.

Main Results:

• Elderly individuals without disabilities appear to utilize a head-first control scheme for self-initiated motion.
• The head-stabilization-in-space (HSS) strategy, primarily geocentric, is employed to maintain head position.
• Preliminary evidence suggests elderly individuals use HSS for head pitch control in challenging balance tasks.

Conclusions:

• The head-first organization scheme, particularly the HSS strategy, is a key mechanism for maintaining head stability in older adults.
• This strategy likely reduces sensory input ambiguity, improving balance and potentially aiding in the treatment of balance disorders.
• Further research is needed to confirm these findings and their clinical implications for balance dysfunction treatment.