The effects of functional instability of the ankle joint on balance

Abstract

BACKGROUND: Individuals who suffer from ankle instability may experience restricted movement and a weakening of the
muscles that support the ankle.
PURPOSE: The aim of this study was to investigate the effects of functional instability of the ankle joint on static and dynamic
balance performances.
METHODS: Twenty-five participants (8 male, 17 female) were recruited for this study. The subjects were divided into two
groups: an ankle instability and a normal ankle stability group. The static and dynamic limits of stability performance were
assessed in single leg standing using the BioRescue device. In addition, the Functional Reach Test (FRT) and the Modified
Functional Reach Test (MFRT) were also recorded.
RESULTS: Significant differences between the two groups were found in the moving distance and the mean velocity of the
center of pressure during the single leg standing test, the pendular limits of stability test, and the MFRT. However, the FRTshowed no significant difference between the two groups. The results showed that the static and dynamic balance performances were reduced in the ankle instability group compared with the control group.
CONCLUSION: Both the MFRT and BioRescue were sensitive and appropriate to identify clinically important differences
between the two groups. The MFRT is a quick and inexpensive clinical measure of postural instability relevant to individuals
with ankle instability. Further studies should use the MFRT to determine the effectiveness of clinical interventions for ankle
instability that target improvements in balance.