The Effect of Intrinsic Foot Muscles Strengthening on the Postural Control Indices in Patients with Chronic Functional Ankle Instability

Abstract

Background: Foot intrinsic muscles are crucial for supporting the foot on the ground. Their activation can play an important role in postural control in functional ankle instability subjects. This study aimed to determine intrinsic foot muscle strengthening exercises’ effect on postural control indices in subjects with chronic functional ankle instability.

Methods: In this randomized clinical trial, 45 subjects with functional ankle instability were included. The subjects were randomly divided into a routine exercise group, an intrinsic muscle-strengthening exercise group, or a control group. Exercises were conducted three times per week for four weeks. Overall, anteroposterior and mediolateral stability indices were measured before and after four weeks with the biodex balance system. Data were analyzed with the paired sample t-test, one-way ANOVA, and Tukey test.

Results: In the intrinsic exercise group, the overall dynamic stability index significantly changed from 1.68±0.8 to 1.24±0.8, the mediolateral dynamic stability index significantly changed from 1.04±0.5 to 0.72±0.3, and the anteroposterior dynamic stability index significantly changed from 1.29±0.5 to 0.84±0.3 (p<0.05). They also have significant changes in the mediolateral dynamic stability index for the affected foot from 2.37±1.4 to 1.53±0.7 and the anteroposterior dynamic stability index for the affected foot from1.81±0.6 to 1.23±0.3 (p<0.05). There is no significant difference in the dynamic stability index between routine and intrinsic groups (p>0.05).

Conclusion: According to the results of the study, the positive effects of foot intrinsic muscle exercise on postural control reactions were shown, so we suggest that in addition to routine exercises, intrinsic exercises should also be considered in subjects with chronic functional ankle instability.