Context: Research has demonstrated individuals with chronic ankle instability (CAI) present with alterations in the compositional structure of the talar articular cartilage. These alterations likely influence how the talar cartilage responds to loading associated with activities of daily living, such as walking. Ultrasonography has emerged as an alternative imaging modality to assess the amount of cartilage deformation in response to loading because it can be clinically accessible and cost-effective for routine measurements.
Objective: To compare talar cartilage deformation in response to a standardized exercise protocol between those with and without chronic ankle instability. Secondly, to examine the association between spatiotemporal walking gait parameters and cartilage deformation.
Setting: Research Laboratory.
Patients or Other Participants: A volunteer sample of 24 participants with self-reported CAI (age = 23.2 ± 3.9 years; BMI = 25.1 ± 3.7 kg/m2) and 24 un-injured controls (age = 24.3 ± 2.9 years; BMI = 22.9 ± 2.8 kg/m2).
Main Outcome Measure(s): Spatiotemporal walking gait was first assessed from five self-selected trials using an electronic walkway with data sampled at 120Hz. An 8-to-13MHz linear-array ultrasound transducer placed transversely in line with the medial and lateral malleoli captured three images before and after a standardized loading protocol consisting of 30 single and double-limb squats, 2-minute single-limb balance and 10 single-leg drops from a 40cm height box.
Results: After controlling for body mass index, participants with chronic ankle instability had greater deformation compared to the un-injured controls (p=0.034). No other significant between group differences were observed (p>0.05). No significant partial correlations were observed between talar cartilage deformation and spatiotemporal gait parameters when controlling for body mass index (p>0.05).
Conclusions: Individuals with CAI had greater talar cartilage deformation in response to a standardized exercise protocol than controls. The amount of talar cartilage deformation was not associated with spatiotemporal walking gait.