Ankle and foot mechanics in individuals with chronic ankle instability during shod walking and barefoot walking: A cross-sectional study

Abstract Objective This study evaluated the angular kinematic and moment of the ankle and foot during shod walking and barefoot walking in individuals with unilateral chronic ankle instability (CAI). Methods Twenty eight recreational soccer players with unilateral CAI were recruited for this cross sectional study. A three dimensional motion analysis system with a force plate was used to assess the ankle and foot angles and moment during shod walking and barefoot walking conditions. Results During shod walking, the ankle joint plantar-flexion range of motion (ROM) at 10% of the gait cycle (GC) and dorsiflexion ROM at 30% of the GC were significantly higher than those during barefoot walking for both feet (p = 0.001, 0.001, 0.027, and 0.036 respectively). The inversion ROM during shod walking was significantly higher than that during barefoot walking for both feet at 10% and 30% of the GC (p = 0.001. 0.001, 0.001, and 0.042 respectively). At 10% of the GC, the eversion moment was significantly higher between barefoot and shod walking for both feet (both p = 0.001). At 30% of the GC, there was no significant difference between shod and barefoot walking plantar-flexion moment of both feet (p = 0.975 and 0.763 respectively), and the eversion moment of both feet (p = 0.116 and 0.101 respectively). Conclusion At the early stance, shod walking increases the ankle plantar-flexion and foot inversion ROM, and decreases the eversion moment for both feet in subjects with unilateral CAI. Therefore, the foot wearing condition should be considered during evaluation of ankle and foot kinematics and kinetics.