Change in Muscle Activities Elicited by Running while Focusing on Ankle Dorsiflexion

Abstract

[Purpose] The purpose of this study was to determine the change in muscle activity and the angle of the lower extremity elicited by running while focusing on dorsiflexion. [Subjects and Methods] Seven collegiate long-distance runners participated in this study. The subjects performed two types of running on a treadmill: normal running (NR), and running with focus on dorsiflexion at heel contact (DR). The muscle activities of the lower extremity were obtained using a wireless sensor. [Results] DR increased the angle between the sole of the foot and the horizontal plane. The angular velocity of dorsiflexion at the absorptive phase was lower during DR. In addition, DR elicited increased activity in the tibialis anterior at pre-heel contact, and in the rectus femoris in the stance phase. [Conclusion] In DR, the decrease in the stretching stress on the Achilles tendon and the increase in the activities of muscles used for shock absorption are expected to diminish the load on the Achilles tendon.