To investigate the effects of wobble board training on the onset of muscle activity and perception of stability in participants with a functionally unstable ankle.Nineteen male participants (Mean age=29.7 years, SD=4.9) who complained of a weak ankle and had sustained at least three sprains in the past 2 years, but no injury for 3 months, a negative anterior draw, normal standing biomechanics, no movement dysfunction, and no cardiac or neurological balance problems.Participants completed a questionnaire on functional stability. Using surface electromyography (sEMG) the onset time of the tibialis anterior (TA) and peroneus longus (PL) were recorded in response to a sudden 20° inversion. Participants were assigned to two groups; control (n=9) and exercise (n=10). The exercise group underwent a monitored 4-week wobble board programme (10min per session, three times per week).Post training, the exercise group showed a significant decrease in muscle onset latency (p<0.05) and a significant improvement in perception of their functional stability (p<0.01).The findings indicate that, even after a short period, wobble board exercise reduces the likelihood of further sprains in individuals with functionally unstable ankles.