Self-Perceived Prevalence of Functional Ankle Instability and Associated Factors Among Male Volleyball Players in Qassim Region

<i>Background and Objectives</i>: Functional Ankle Instability (FAI) is a sequela of ankle sprains; however, its associated variables in volleyballers have not been studied. This study aimed to determine the prevalence of FAI and the association between FAI and its associated variables in volleyball players. <i>Materials and Methods</i>: An observational study with a sample size of 128 male volleyballers, aged 18 years and older, was conducted using the Arabic-Identification of Functional Ankle Instability (Ar-IdFAI) questionnaire. The prevalence of FAI was analyzed in terms of frequency and percentage. The Mann-Whitney U test, Spearman's test, and <i>t</i>-test were used to analyze the associations between the demographic variables and the categorical variables, and a logistic regression model was applied to identify the independent associations with FAI. Statistical significance was set at <i>p</i> < 0.05. <i>Results</i>: The prevalence of FAI in the sample was 44.53%. Bivariate analysis and the regression model indicated no significant direct association between FAI and age, Body Mass Index (BMI), playing duration, weekly training hours, or limb dominance in this sample. Conversely, historical injury burden showed strong and statistically significant associations with FAI (Cramér's V = 0.59-1.00), with "giving way" demonstrating perfect separation. The logistic regression model showed an acceptable fit (<i>p</i> = 0.676) and moderate explanatory power (Nagelkerke R² = 0.540), with excellent discriminatory performance Area Under the Curve (AUC = 0.855) driven primarily by injury-related variables. <i>Conclusions</i>: FAI is highly prevalent among male volleyball players and is linked to injury history rather than demographic or training characteristics. Injury-related characteristics, including previous ankle injury, reinjury, and episodes of ankle "giving way", demonstrated strong associations with the presence of Functional Ankle Instability, to be interpreted as descriptive associations rather than a causal link due to methodological structure.