Effect of soft and semirigid ankle orthoses on Star Excursion Balance Test performance in patients with functional ankle instability.

Objectives: To evaluate the effect of soft and semirigid ankle orthoses on dynamic balance assessed using Star Excursion Balance Test in patients with functional ankle instability compared with healthy individuals.

Design: Non-experimental, observational study with multiple-factor design, including group (functional ankle instability and healthy) as the between-subjects factor and orthotics condition (no orthosis, soft orthosis and semirigid orthosis) as the within-subjects factor.

Methods: Sixteen unilateral functional ankle instability patients and a group of 16 healthy control individuals, matched for age, height and weight, participated in the study. Dynamic balance was tested with and without wearing ankle orthosis. Reach distance of participants in 3 bracing conditions were measured in anteromedial, medial and posteromedial directions of Star Excursion Balance Test. Average of 3 trials in 3 measured directions, normalized to leg length of each participant, was used for statistical analysis.

Results: There were no differences among orthotics conditions in healthy people. However, normalized reach distance increased from no-orthosis to semirigid to soft orthoses in FAI patients. Differences were significant between soft and no-orthosis (13% in anteromedial, 14% in medial and 15% in posteromedial direction p=0.01) and between semirigid and no-orthosis (10% in anteromedial, 8.5% in medial and 8.5% in posteromedial direction, p=0.01) conditions in all 3 measured directions. The difference between soft and semirigid orthoses was significant (6% difference, p<0.05) only in PM direction.

Conclusions: Ankle orthoses improve reach distance in functional ankle instability patients in various reach directions. Soft orthosis has a more pronounced effect on dynamic balance, especially in posteromedial direction, compared with semirigid orthosis.