The Activities of the Muscles around the Ankle Joint during Foot-gripping are Affected by the Angle of the Ankle

[Purpose] The purpose of this study was to determine the activities of the muscles around the ankle joint during foot gripping. [Subjects] The subjects of this study were 17 healthy females. [Methods] We measured the maximum voluntary contraction (MVC) activities of the soleus muscle, the medial head of the gastrocnemius muscle, and the tibialis anterior muscle, and calculated %IEMG during foot gripping in 3 different ankle joint positions: 10° of plantar flexion, 0°, and 10° of dorsiflexion. [Results] The maximal force of foot gripping achived by the crural muscles in any ankle position was 30–50% IMEG of the MVC. Repeated analysis of variance showed that the %IEMG was significantly lower in 10°of dorsiflexion than in the other 2 positions for all muscles. [Conclusion] These results suggested that the crural muscles help the ankle joint by co-contracting during foot gripping.