P21 The relationship between centre of pressure and body mass index in individuals with chronic ankle instability

Abstract

Study Design Cross-sectional. Objectives To identify differences in centre of pressure (COP) and BMI among control, coper, and CAI participants and the relationship between COP and BMI across groups. Background Chronic ankle instability (CAI) is a frequent and serious repercussion of lateral ankle sprains. Individuals with larger mass have a higher probability of developing CAI. Those with CAI have also demonstrated differences in COP while maintaining postural stability compared to healthy controls. However, it’s unclear if body mass index (BMI) has an effect on the COP of individuals with CAI. Methods and Measure 45 individuals (18male, 27female: age=22.5±2.67 years, height=171.2±9.5 cm, mass=72.1±12.8 kg) participated in this study. Subjects were classified into three groups (CAI, coper, or control). All participants performed a single-leg balance test on a force platform (100 Hz) for 60 s. BMI, COP range (COP-R) in the anterior-posterior (AP) and medial-lateral (ML) directions were calculated. Differences (p≤0.05) among groups were assessed with an analysis of variance (ANOVA). Pearson’s correlational coefficients were conducted to assess the relationships between BMI and COP (p≤0.05). Results There were no differences in BMI (Control=25.5±3.9 kg/m2, Coper=23.9±2.7 kg/m2, CAI=24.2±3.9 kg/m2, p=0.42) or COP variables (COP-AP: Control=37.3±8.7 mm, Coper=41.6±11.7 mm, CAI=42.1±13.9 mm, p=0.47; COP-ML: Control=30.16±7.11 mm, Coper=30.8±6.1 mm, CAI=30.8±5.0, p=0.94). BMI was significantly, moderately correlated with deviations in COP-R-ML in individuals with CAI (r=0.451, p=0.05). No other correlations (p>0.05) were significant between BMI and COP variables. Conclusions A moderate correlation existed between BMI and ML postural control in those with CAI, but was not present in the other groups. Thus, in those with CAI, higher levels of BMI may be a moderator of poor postural stability, potentially compounding deficiencies. Further research is necessary in order to explore this relationship between BMI and COP to identify if reducing BMI improves outcomes in individuals with CAI.