Correlations of strength, proprioception, and dynamic balance to the Cumberland Ankle Instability Tool Score among patients with chronic ankle instability: a cross-sectional study.

Abstract

Background: The Cumberland Ankle Instability Tool (CAIT) is used to screen patients with chronic ankle instability (CAI) and to quantify the severity of ankle instability. Neuromuscular deficits are common in CAI, including proprioception, strength, and balance issues. The relationship between CAIT scores and neuromuscular factors is unclear. The purpose of this study was to investigate the correlation between ankle instability and ankle muscle strength, proprioception, and dynamic balance.

Methods: Thirty-four individuals with chronic ankle instability were included in this study. The participants' CAIT scores, muscle strength (isokinetic) and proprioception in plantarflexion (PF), dorsiflexion (DF), inversion (IV), and eversion (EV), and dynamic balance (Star Excursion Balance Test in anterior, posteromedial, and posterolateral directions) were assessed. Bivariate correlations were used to determine the relationship between CAIT scores and ankle muscle strength, proprioception, and dynamic balance.

Results: In terms of muscle strength, ankle PF (r = 0.378, 95%CI: 0.046-0.635, P = 0.027) and IV (r = 0.527, 95%CI: 0.233-0.736, P = 0.001) strength were positively correlated with CAIT Score, whereas ankle DF and EV strength had no significant correlation with CAIT Score. In terms of proprioception, ankle IV proprioception (r = -0.340, 95%CI: -0.608-0.002, P = 0.027) was negatively correlated with CAIT Score, while ankle PF, DF, and EV proprioception had no significant correlation with CAIT Score. In terms of dynamic balance, the SEBT posteromedial (r = 0.444, 95%CI: 0.124-0.680, P = 0.001) was positively correlated with CAIT Score. The SEBT anterior and posterolateral were not significantly correlated with the CAIT Score.

Conclusion: This study found that increasing ankle plantarflexion and inversion muscle strength, improving dynamic balance in the posteromedial direction, and decreasing ankle inversion proprioceptive thresholds may help improve the subjective stability of CAI. This provides data support for targeted ankle neuromuscular function rehabilitation training for patients.

Trial registration: Chinese Clinical Trial Registry ChiCTR2100044089. Registered on 10 March 2021.