Effects on Ankle Muscle Activity of the Tilt Direction of a Balance Board

[Purpose] This study aimed to investigate the effects of different levels of stability and tilt directions of balance boards on lower leg muscle activity. [Subjects and Methods] Sixteen healthy adults were tested. Each subject stood on a balance board with their non-dominant leg. Balance boards with two different degrees of instability were used. Data on activities of the tibialis anterior and the peroneus longus were recorded under three different exercise conditions: quiet stance, balance board tilting in the dorsiflexion/plantarflexion direction and in the adduction/abduction direction. [Results] Muscle activity was significantly higher on the less stable balance board. A significantly higher peroneus longus activity relative to that of the tibialis anterior was observed when the board was tilted in the plantarflexion and abduction directions. [Conclusion] Tilting a balance board in the plantarflexion and abduction directions may generate a muscle activity pattern that may help correct excessive inversion movement of the ankle.