3D analysis of the metatarsophalangeal joint in normal group and Hallux valgus patients during walking using a four-segment foot model

The purpose of this study was to determine the kinetic role of the metatarsophalangeal (MP) joint during barefoot walking in both a normal group and hallux valgus (HV) patients. Three-dimensional motion analysis with foot pressure measurements was performed. Ten normal subjects and ten HV patients were selected for the study. Results showed that a significant difference in stance time between the normal and HV groups (p<0.05). Joint moments gradually increased and became maximal at the beginning of pre-swing. No difference was found in the MP joint moments between the two groups. Significant amount of energy absorption was observed from the terminal stance to pre-swing in both groups. However, total energy absorption in all MP joints decreased 25% in the HV group (4.59±0.85 J/kg) compared with the normal group (6.09±1.00 J/kg). The energy absorption in the 1st MP joint and the 2nd MP joint were significantly smaller in the HV group than in the normal group (p<0.05). The four-segment foot model used in this study demonstrated the lateral load transfer from the 1st MP joint to the lateral MP joints for HV patients. This study would be very helpful to determine the kinetic role of MP joints in HV patients.