Introduction:
This study aimed to compare the effects of balance and plyometric training on balance control among individuals with functional ankle instability (FAI).

Methods:
Overall, 20 individuals with FAI, classified in balance (n = 10) and plyometric (n = 10) training groups, participated in the study. Testing variables included standard deviations and ranges of centre of pressure in mediolateral (ML-COPsd/ML-COPr) and anteroposterior (AP-COPsd/AP-COPr) directions during single-legged stance with eyes open and closed, times to stabilization of ground reaction force in mediolateral (ML-TTS) and anteroposterior (AP-TTS) directions during step-down, and reach distances in anterior, posteromedial, and posterolateral directions from the modified Star Excursion Balance Test.

Results:
When comparing between the groups, the plyometric training group exhibited a significant reduction of ML-COPsd with eyes open after 6 weeks of training (p = 0.004) and shorter ML-TTS and AP-TTS after 4 weeks (p = 0.009 and p = 0.007) and 6 weeks (p = 0.011 and p = 0.029) of training. For within-group comparison, the plyometric training group showed significant improvements (p < 0.05) in all testing variables, whereas the balance training group presented improvement only in the reach distances.

Conclusions:
Plyometric training provided benefits in both static and dynamic balances for individuals with FAI.