Background: Clinicians employ foot morphology assessment to evaluate the functionality of the method and anticipate possible injuries. This study aims to correlate static foot posture and the dynamic barefoot evaluation in a sample of healthy adult participants.
Methods: The foot posture was evaluated using the Foot Posture Index-6 (FPI-6) and the dynamics were evaluated through baropodometric examination. Two operators independently assessed the participants' foot posture through FPI-6, and then a dynamic evaluation was performed by asking them to walk 8 times across a platform. One hundred participants (mean age: 32.15 ± 7.49) were enrolled.
Results: The inter-rater agreement between the two assessors was found to be excellent. The majority of the feet belonged to the 0 < FPI < 4 class (32%), followed by the 4 < FPI < 8 (31%) and the FPI > 8 ranges (19.5%). Our "area of contact" analysis showed a significant poor correlation between FPI and total foot, midfoot, and the second metatarsophalangeal joint (MTPJ) (-0.3 < r < 0). Regarding "force" parameters, the analysis showed a poor correlation between the midfoot, hallux, and the second toe (-0.2 < r < 2); finally the "pressure" analysis showed a poor correlation between FPI, the fourth MTPJ, and the second toe (-0.2 < rs < 0.3) and a moderate correlation between the hallux (r = 0.374) and the fifth MTPJ (r = 0.427).
Conclusions: This study emphasizes the constrained correlation between static foot posture observation and dynamic barefoot examination.
Keywords: flat feet; foot morphology; foot posture index; gait analysis; hyperpronation; pes planus; plantar foot pressure.