Abstract: BACKGROUND: Chronic ankle instability occurs mostly during landing and side-cutting tasks. Taping is one of the most commonly used means of ankle sports protection, but the mechanism of action is controversial, and whether taping can limit ankle motion in patients with chronic ankle instability during functional activities and affect the knee joint to compensatory variation still needs further exploration.

OBJECTIVE: To determine the effect of ankle taping on knee and ankle biomechanics in patients with chronic ankle instability during the side-cutting and stop-jumping tasks.

METHODS: Thirteen patients with chronic ankle instability (trial group) and thirteen healthy male college students (control group) were enrolled. Each participant performed the biomechanical tests with and without the basketweave ankle taping. The kinematic and kinetic data during 45° side-cutting and stop-jumping were synchronously collected by Vicon motion capture system and AMTI forceplates. A two-way repeated measures analysis of differences was performed to determine the effects of taping and group on knee and ankle angles and moments during the stance phase of side-cutting and stop-jumping. 
RESULTS AND CONCLUSION: (1) There was an interaction effect between taping and group on the peak ankle valgus angle during stance phase of stop-jumping (P=0.034). The ankle valgus angle in the trial group with taping was significantly lower than that in the trial group without taping (P=0.006), while the ankle valgus angle in the trial group with taping was significantly lower than that in the control group with taping (P=0.024). (2) There was an interaction effect between taping and group on the peak knee valgus moment during the stance phase of stop-jumping (P=0.027). The knee valgus moment in the trial group with taping was significantly lower than that in the trial group without taping (P=0.003). (3) No interaction effect between taping and group on peak ankle plantarflexion moment (P=0.977), peak knee extension moment (P=0.281) during stance phase of stop-jumping, and peak ankle valgus angle (P=0.211) during the stance phase of side-cutting was detected. Taping significantly decreased these three variables (P ≤ 0.019). (4) Taping showed no significant effects on other knee and ankle angles and moments during the stance phase of side-cutting and stop-jumping (P ≥ 0.053). Therefore, ankle taping decreased the peak ankle valgus angle and peak knee valgus moment of patients with chronic ankle instability during the stance phase in stop-jumping task compared with the healthy controls, suggesting that taping may better limit ankle valgus and knee joint loading.

Key words: ankle taping, chronic ankle instability, ankle, knee, kinematics, kinetics, biomechanics