The Influence of Hallux Valgus on Plantar Pressure During Walking

Background: Foot deformities such as hallux valgus can be one of the causes of falls for the elderly. This is a serious social problem, and a quantitative method for evaluating the effects of such foot deformities is desirable. This study examines the relationship between plantar pressure during the act of walking and the presence (or absence) of hallux valgus. Method: Foot-pressure data during walking was recorded using an F-scan II system. Gait experiments over a 10-m walkway using the plantar pressure system were conducted with 28 female participants (12 with hallux valgus, and 16 without). We analyzed the entire waveform of the plantar pressure data taken during walking using principal component analysis (PCA). Data analysis was conducted using a 280 × 357 matrix of time-normalized plantar data of 7 areas during gait (5 gait trials × 2 (both feet) of 28 subjects × 51 data points × 7 plantar areas). One-way analysis of variance was conducted on the principal component scores (PCSs) of principal component vectors (PCVs) 1–37 and demographic data, each of which exhibited a variance of greater than 5%. Results: The first group comprised of subjects with hallux valgus affecting one foot only. In the second group, the unaffected foot was considered. The third group did not have hallux valgus affecting either foot. The PCA clarified that the 2nd, 7th, 11th, and 15th PCVs were related to the effects of the presence or absence of hallux valgus ($p < 0.05$). These results indicated that hallux valgus affected foot pressure during walking. Moreover, those with hallux valgus tended to have different plantar pressure variations in the entire plantar area, while those with normal feet did not experience such variations. Benefit of this research: Our results indicated the possibility of differences in the characteristics of plantar pressure during the stance phase in gait events, based on the PCVs of the presented groups. The evaluation of foot pressure during everyday walking will help in the prevention of unilateral and bilateral hallux valgus; hence, helping to prevent falls.