Background: A few studies have investigated the relationship between foot posture measures and plantar pressure parameters, but no study has investigated the correlation of foot posture measures with all primary parameters consisting of contact area (CA), maximum force (MF), and peak pressure (PP). We aimed to determine the relationship of the Foot Posture Index-6 (FPI-6) and navicular drop (ND) with plantar pressure parameters during static standing and preferred walking.
Methods: Seventy people were included. Navicular drop and the FPI-6 were used to assess foot posture. Plantar pressure parameters including CA, MF, and PP were recorded by a pressure-sensitive mat during barefoot standing and barefoot walking at preferred speed. All assessments were repeated three times and averaged. Pearson correlation coefficients below 0.300 were accepted as negligible and higher ones were interpreted.
Results: Navicular drop was moderately correlated with dynamic CA under the midfoot and second metatarsal; also, the FPI-6 was moderately correlated with dynamic CA under the midfoot (0.500 < r < 0.700). The other interpreted correlations were poor (0.300 < r < 0.500). Both measures were correlated with dynamic CA under the second and third metatarsals; dynamic CA and MF under the midfoot; and static CA, MF, and PP under the first metatarsal and hallux (P < .01). Navicular drop was also correlated with dynamic MF under the first metatarsal and dynamic CA under the fourth metatarsal (P < .01). Furthermore, ND was correlated with static CA and PP under the second metatarsal and static PP under the fifth metatarsal (P < .01). The FPI-6 was also correlated with dynamic MF and PP under the hallux (P < .01).
Conclusions: The correlations between foot posture measures and plantar pressure variables are poor to moderate. The measures may be useful in the clinical assessment of medial forefoot problems related to prolonged standing and midfoot complaints related to high force during walking. Furthermore, the FPI-6 may provide valuable data regarding hallux complaints related to the high loads during walking.