Unfortunately rolled ankles are pretty common in karate. This is especially true for people who spend a great deal of time walking on the sides of their feet in order to condition them for sokuto (foot edge) strikes. Stretching the outside of the ankles results in ankle instability and this can present a real danger for people working in groups that emphasize sweeps and throws in conjunction with strikes.
In the group I teach we no longer use sokuto for larger yoko-geri (side kicks), instead we use the sole of the foot (closer to the heel). Striking with sokuto with a strong yoko geri results in a great deal of compression on the outside of the foot that can result in Morton’s neuroma, ankle injuries, and knee damage. We still use sokuto for the smaller kansetsu geri (knee kicks) as not as much force is required for it to be effective.
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