Changes in talocrural and subtalar joint kinematics of barefoot versus shod forefoot landing

BACKGROUND Synergetic talocrural and subtalar joint movements allow adaptation to different footwear and/or surface conditions. Therefore, knowledge of kinematic differences between barefoot and shod conditions is valuable for the study of adaptations to footwear conditions. The objective of this study was to assess the kinematic differences in the talocrural and subtalar joints during barefoot and shod landing. METHODS Seven healthy participants (4 males and 3 females) participated in a landing trial under barefoot and shod conditions. Fluoroscopic images and forceplate data were collected simultaneously to calculate the talocrural and subtalar joint kinematics and the vertical ground reaction force. RESULTS Upon toe contact, the plantarflexion angle of the talocrural joint during the barefoot condition was significantly larger than that during the shod condition (barefoot, 20.5 ± 7.1°, shod, 17.9 ± 8.3°, p =0.03). From toe contact to heel contact, the angular changes at the talocrural and subtalar joint were not significantly different between the barefoot and shod conditions; however, the changes in the subtalar eversion angles in the barefoot condition, from heel contact to 150 ms after toe contact, were significantly larger than those in the shod condition. CONCLUSIONS These results suggest that footwear was able to reduce the eversion angle of the subtalar joint after heel contact during landing; the effect of wearing footwear was quite limited. Therefore, induced rearfoot kinematic alterations to prevent or manage injuries by neutral-type footwear are likely to be impractical.