OBJECTIVE: To examine the effects of ankle joint taping and exercise on ankle joint sagittal plane and rear-foot frontal plane movement in subjects with chronic ankle instability. DESIGN: Laboratory-based, repeated-measures study. SETTING: University biomechanics laboratory. PARTICIPANTS: Subjects with chronic ankle instability (N=11) as defined by the Cumberland Ankle Instability Tool. INTERVENTIONS: Each participant performed 3 single-leg drop landings onto a forceplate under 3 different conditions. These conditions were: condition 1 (no tape), condition 2 (taped), and condition 3 (postexercise taped). MAIN OUTCOME MEASURES: Kinematic data were used to identify ankle joint sagittal plane and rear-foot frontal plane positions at 50 ms before initial contact (IC) and at IC, under each of the conditions. RESULTS: There was a significant effect on the angle of ankle joint plantar flexion, both at 50 ms before IC (F(2,18)=29.4, P<.001) and at IC (F(2,18)=16.1, P<.001), as a result of the application of tape. Post hoc analysis revealed that condition 1 (no tape) resulted in significantly greater plantar flexion angle at 50 ms before IC than condition 2 (taped) (7.7+/-3.0 degrees ; P=.002) and condition 3 (postexercise taped) (8.3+/-4.8 degrees ; P=.01). Similarly, condition 1 (no tape) resulted in significantly greater plantar flexion at IC than both condition 2 (taped) (5.3+/-3.2 degrees ; P<.001) and condition 3 (postexercise taped) (5.3+/-4.4 degrees ; P=.001). No significant differences were evident between condition 2 (taped) and condition 3 (postexercise taped) (P>.05). CONCLUSIONS: These results indicate that taping acted to reduce the degree of plantar flexion at both 50 ms before and at IC with the ground, and that these reductions were retained even after exercise.