Evaluation of different hindfoot kinematics according to various shoe types during walking using biplanar fluoroscopy

Unlike Skin marker-based models, biplanar fluoroscopy can evaluate the kinematic effects of various shoes. This study investigated foot and ankle kinematics across various shoe types during walking using a biplanar fluoroscopic system. Fifteen healthy participants were enrolled. All participants underwent three-dimensional (3D) computed tomography, and biplanar fluoroscopic images were captured during the stance phase of gait for barefoot and three different shoe types. 3D kinematic data of the ankle and subtalar joints were calculated using the anatomical coordinate system through the 3D/2D registration method. Running shoes (RS) significantly reduced maximum ankle dorsiflexion (p = 0.007), hindfoot dorsiflexion (p = 0.001) compared with barefoot. Rocker bottom shoes (RBS) reduced ankle and hindfoot DF-PF ROM (p < 0.001), and increased subtalar ROM by increasing subtalar plantarflexion(p = 0.047). Climbing shoes reduced the peak hindfoot dorsiflexion (p < 0.001), and ankle dorsiflexion (p = 0.013). High heels (HH) caused significant ankle (p < 0.001) and hindfoot (p < 0.001) plantar flexion, along with increased hindfoot inversion (p = 0.008) and internal rotation (p = 0.003). In conclusion, Shoed walking reduced dorsiflexion compared with barefoot walking, potentially benefiting conditions such as anterior ankle impingement. RBSs may alleviate arthritis symptoms by limiting motion, whereas HHs increase hindfoot inversion, potentially increasing the risk of ankle injury and long-term joint damage.