Determination of factors affecting balance in adults with chronic ankle instability

Chronic Ankle Instability (CAI) is a clinical condition characterized by recurrent sprains, pain, balance loss, and a sense of instability, resulting from disruptions in the sensorimotor system. This condition may affect not only peripheral structures but also central nervous system adaptations, leading to postural control impairments. This study aimed to examine the relationship between static and dynamic balance and ankle muscle strength (dorsiflexion and plantar flexion), pain level, kinesiophobia, physical activity level, and quality of life in individuals diagnosed with CAI; to compare these parameters with healthy individuals; and to identify clinical determinants affecting balance. The study included 24 individuals with CAI and 24 healthy volunteers matched demographically. Static balance was assessed using the Single Leg Stance Test, and dynamic balance was evaluated with the Stability Limits Test using the ALFA stabilometric platform. Ankle muscle strength was evaluated using an isokinetic dynamometer, pain level was assessed with the Visual Analog Scale (VAS), kinesiophobia was measured with the Tampa Scale for Kinesiophobia, physical activity level was determined with the short form of the International Physical Activity Questionnaire (IPAQ), and quality of life was evaluated with the SF-36 survey. Statistical analyses were conducted using SPSS v26.0. Continuous variables were reported as mean ± standard deviation, and categorical variables as numbers and percentages. Normality of data distribution was assessed. Independent Samples T-test or Mann-Whitney U test was used for group comparisons, Pearson or Spearman correlation for relationships, and multiple linear regression analysis for predictive modeling. Statistical significance was set at p<0.05. The results showed that the CAI group had significantly lower static (p<0.001) and dynamic balance scores (p=0.024), reduced dorsiflexion (p=0.039 and p=0.045) and plantar flexion (p=0.040 and p=0.036) muscle strength, higher pain levels (p<0.001) and kinesiophobia (p=0.027), and lower physical activity levels (p=0.031). Quality of life scores were significantly lower in the CAI group for physical function (p<0.001), role-physical (p=0.003), pain (p=0.001), vitality (p=0.005), social functioning (p=0.006), emotional role (p=0.038), physical component summary (p<0.001), and mental component summary (p=0.004). Static balance was positively correlated with dorsiflexion strength (r=0.550; p=0.007) and plantar flexion strength (r=0.477; p=0.018), and negatively with pain level (r=-0.424; p=0.039). Dynamic balance was positively correlated with dorsiflexion strength (r=0.374; p=0.039) and role-physical score (r=0.354; p=0.040). Regression analyses revealed that dorsiflexion (p=0.001), plantar flexion (p=0.002) strength, and pain level (p=0.006) were significant predictors of static balance, while dorsiflexion strength (p=0.003) and role-physical score (p=0.009) predicted dynamic balance. In individuals with CAI, impaired static and dynamic balance was significantly associated with reduced muscle strength, increased pain, lower physical activity, and diminished quality of life. These findings highlight the importance of holistic rehabilitation approaches targeting multiple physical and psychological determinants of balance.