Relationship of Isokinetic Strength of Ankle Evertors and Invertors with Dynamic Postural Stability in Team Sport Players

Abstract

Background: Foot stability is essential for performing various dynamic movements in sports. The contribution of ankle dorsiflexors and planter flexors co-contraction in maintenance of postural balance is mainly the focus of previous studies. However, whether there is any role of ankle evertors and invertors in maintaining foot stability while doing dynamic postural tasks is not well studied so far. Aim: The aim of this study was to find out if there is a correlation of isokinetic strength of ankle evertors and invertors with dynamic postural stability. Setting and Design: This cross-sectional study was conducted in the Strength Analysis Lab of the university. Subjects and Methods: Thirty-five male team sport players (9 – football, 9 – hockey, 9 – basketball, and 8 – volleyball) with mean age: 20.6 ± 1.83 years, body weight: 62.2 ± 8.36 kg, and height: 172.3 ± 8.07 cm were included. Balance was measured with lower quarter-Y-balance test whereas isokinetic strength of ankle evertors and invertors was measured with Biodex dynamometer. Statistical Analysis: In the statistical software SPSS, Kolmogorov–Smirnov test was applied to check the normality of data. As the data were normally distributed, the relationship between variables was found by Pearson’s correlation coefficient. Results: Isokinetic strength of right ankle invertors was moderately correlated with composite reach of the left limb at 30°/s angular velocity (P = 0.027). Composite reach right limb was moderately correlated with isokinetic strength of the right ankle evertors at 30° and 60°/s angular velocities (P = 0.043 and 0.022). Composite reach of the right limb was moderately correlated with isokinetic strength of right ankle invertors at 60° and 90°/s angular velocities (P = 0.046 and 0.046). Conclusion: Isokinetic strength of ankle evertors and invertor is significantly related to dynamic postural stability and should be included in fitness programs, especially for injury prevention and to improve dynamic postural stability.