Spatiotemporal postural control deficits are present in those with chronic ankle instability

Area of Science:

• Biomechanics
• Motor Control
• Sports Medicine

Background:

• Chronic ankle instability (CAI) is often associated with postural control deficits.
• Traditional forceplate measures have inconsistently identified these deficits in CAI.
• Time-to-boundary (TTB), a dynamical systems measure, shows promise for detecting CAI-related postural control impairments.

Purpose of the Study:

• To investigate postural control in males and females with and without CAI using TTB measures.
• To compare TTB measures between individuals with CAI and healthy controls across different visual conditions.

Main Methods:

• A case-control study involving 32 participants (18 males, 14 females) with CAI and matched controls.
• Participants performed single-limb stance on a forceplate with eyes open and closed.
• Key outcome measures included TTB minima (absolute, mean, standard deviation) in anteroposterior and mediolateral directions.

Main Results:

• No significant group by gender interactions or gender main effects were found.
• Significant group main effects for TTB measures were observed with eyes closed, indicating deficits in the CAI group.
• No significant differences in TTB measures were detected between groups with eyes open.

Conclusions:

• TTB deficits were identified in the CAI group compared to controls, specifically when visual input was removed.
• The findings suggest that CAI imposes greater constraints on the sensorimotor system during single-limb stance.
• These TTB deficits may reflect an impaired ability to adapt to changing postural demands in individuals with CAI.