Postural adaptations within normalized stability between older adults with and without chronic low back pain

Area of Science:

• Gerontology
• Biomechanics
• Neurology

Background:

• Dynamic balance and sway excursions are linked to chronic low back pain (LBP) in older adults.
• Postural control mechanisms within varying center of pressure (COP) thresholds remain under-investigated in LBP populations.

Purpose of the Study:

• To compare normalized stability using time-in-boundary (TIB) during repeated unilateral limb standing.
• To differentiate postural control between older adults with and without chronic LBP across stability thresholds.

Main Methods:

• 26 older adults with chronic LBP and 39 age-matched controls performed three trials of unilateral limb standing on a force plate.
• Time-in-boundary (TIB) was analyzed across seven predefined sway thresholds (radii from COP).

Main Results:

• A significant group-by-threshold interaction for TIB was observed (F = 8.76, p = 0.01).
• The LBP group exhibited significantly lower TIB within 10, 15, and 20 mm thresholds during the second trial.
• No significant group differences in TIB were found in the first and third trials, suggesting compensatory strategies.

Conclusions:

• Older adults with LBP demonstrate impaired postural stability within smaller sway radii (<20 mm) during the second trial of unilateral standing.
• The interaction between groups and sway thresholds suggests adaptive postural control strategies in response to LBP.
• These findings underscore the importance of considering sway threshold adaptations and fall prevention in older adults with LBP.