Effect of Foot Position on Ankle Muscle Activity During Wobble Board Training in Individuals With Chronic Ankle Instability.

OBJECTIVE

The purpose of this study was to compare the effects of foot positioning on muscle activities of the peroneus longus (PL), medial gastrocnemius (MG), and tibialis anterior (TA)/PL ratio in individuals with chronic ankle instabilities (CAI) during wobble board training.

METHODS

Thirty individuals with CAI were included, and statistical significance of PL and MG muscle activities was determined using 1-way repeated measures analysis of variance alongside TA/PL activity ratio at the university research laboratory. The participants performed the wobble board training in 3 different foot positions: medial from the centerline of the wobble board (WBT-M), middle from the centerline of the wobble board, and lateral from the centerline of the wobble board (WBT-L). Peroneus longus, MG, and TA muscle activities were measured using surface electromyography.

RESULTS

Peroneus longus activity was significantly higher in the WBT-L position than in the other 2 positions, and it was significantly higher in the middle from the centerline of the wobble board than in the WBT-M position. Medial gastrocnemius activity was significantly greater in the WBT-L position than in the other 2 positions. Tibialis anterior/PL ratio was higher in the WBT-M position than in the other 2 positions.

CONCLUSION

The findings of this study showed that WBT-L increased PL muscle activity by >70% of the maximal voluntary isometric contraction without increasing TA/PL ratio in individuals with CAI.