Abstract: Background: Ankle fractures are among the most common traumatic fractures and have a great socio-economic impact. Consequences of an ankle fracture requiring surgical treatment (e.g. pain, reduced ankle range of motion (ROM), muscle weakness, etc.) lead to balance deterioration, which has a profound impact on activities of daily living. However, to the best of the authors' knowledge, no reliable clinical tests are available to monitor balance in patients after ankle surgery.
Objectives: To quantify single-leg dynamic balance in patients with bimalleolar ankle fracture through the Y-Balance test (YBT). The second objective was to analyze the impact of ankle dorsiflexion ROM and hip strength on balance to optimize balance rehabilitation programs.
Design: Cross-sectional study.
Methods: 22 participants, who had undergone surgery after bimalleolar ankle fractures, were assessed for ankle ROM, hip strength, and dynamic balance six-months after the surgical intervention. The within-session reliability of YBT was calculated through the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). Student's t-tests were used to assess leg differences. A multiple regression analysis was performed to evaluate the role of ankle dorsiflexion ROM and hip abductor and adductor strength in predicting balance performance.
Results: YBT showed high-to-excellent within-session relative reliability (Healthy leg: 0.85 ? ICC?0.96; Operated leg: 0.84 ? ICC?0.96). SEM values were below 3.3 %. The operated leg showed significant lower YBT scores for anterior reach direction (-9.0 %; g=-0.70) and composite score (-4.5 %; g=-0.34). Multiple regression analysis showed that both, ankle dorsiflexion and hip abductor and adductor strength explained 66 % of the variance in the YBT anterior direction of the operated leg.
Conclusions: The YBT is a reliable tool that allows the quantification of single-leg dynamic balance impairments from 6-months after surgery in patients with bimalleolar ankle fracture. Between-leg YBT differences in the anterior direction can be used as reference scores (3.3 %) for balance restoration. Balance rehabilitation programs should focus on improving ankle functionality and reducing hip muscle weakness with specific hip strength exercises and balance exercises with similar demands to the reaching tasks of the YBT to promote a faster recovery.
