Those with chronic ankle instability (CAI) demonstrate deleterious changes in talar cartilage composition, resulting in talar cartilage loading behavior alterations. Common impairments associated with CAI may play a role in cartilage behavior in response to mechanical loading.
The purpose of this study was to identify mechanical and sensorimotor outcomes that associate with the magnitude of talar cartilage deformation following a static loading protocol in those with and without CAI.
A cross-sectional study.
A laboratory setting.
30 CAI and 30 healthy individuals.
After a 60-minute off-loading period, ultrasonographic (US) images of the talar cartilage were acquired immediately before and after a 2-minute static loading protocol (single-leg stance). Talar cartilage images were obtained and manually segmented to calculate medial, lateral, and overall average talar thickness. The percent change, relative to the average baseline thickness, was used for further analysis. Mechanical (ankle joint laxity) and sensorimotor (static balance and star excursion balance test (SEBT)) outcomes were captured. Partial correlations were used to determine associations between cartilage deformation magnitude and the mechanical and sensorimotor outcomes after accounting for bodyweight.
Within the CAI group, greater inversion laxity was associated with greater overall (r=− 0.42, p=0.03) and medial (r=−0.48, p=0.01) talar cartilage deformation following a 2-minute static loading protocol. Similarly, poorer medial-lateral static balance associated with greater overall (r=0.47, p=0.01) and lateral (r=0.50, p=0.01) talar cartilage deformation. Within in control group, shorter posterolateral SEBT reach distance associated with greater lateral cartilage deformation (r=0.42, p=0.03). No other significant associations were observed.
In those with CAI, inversion laxity and poor static postural control moderately associate with greater talar cartilage deformation following a 2-minute static loading protocol. These results suggest that targeting mechanical instability and poor balance in those with CAI via intervention strategies may improve how talar cartilage responds to static loading conditions.