Numerous ankle sprains have been reported in female players performing noncontact play such as side-cutting maneuvers. This study examined the coordination between foot joints during unanticipated side-cutting maneuvers in female soccer players under various cutting angles.

Twelve healthy female soccer players performed unanticipated side-cutting maneuvers in three directions (anterolateral, lateral, and posterolateral). The stance phase was time-normalized and categorized into three phases, namely loading response, deceleration, and propulsion. A modified vector coding technique was used to quantify the coupling angle between the rearfoot, midfoot, and forefoot on the cutting side, which indicates intra-joint coordination, and categorizes the angle into four distinct coordination patterns.

Compared with anterolateral cutting maneuvers, posterolateral cutting maneuvers considerably increased the proportion of in-phase with distal dominancy in the rearfoot vs. midfoot (p ​= ​0.011) during the loading response and in-phase with proximal dominancy in the midfoot vs. forefoot (p ​= ​0.049) during the propulsion phase. During sharp-angle side-cutting maneuvers, the ankle dorsiflexion angle decreased (anterolateral vs. posterolateral: p ​< ​0.001, lateral vs. posterolateral: p ​= ​0.005), and the ankle inversion angle increased (anterolateral vs. lateral: p ​< ​0.001) in most of the stance phase.

The intra-foot coordination pattern of the ankle joint during unanticipated side-cutting maneuvers with sharper angles indicated an increased risk of lateral ankle sprain.