Chu Wang1, Wei Chen2, Yanqiu Xiao3, Jie Yao4*
1Trauma Rescue and Treatment Center, Peking University People’s Hospital, 100044, Beijing, PR China - 2Rokab Pedorthic Center, Water cube, Chaoyang District, 100029, Beijing, China - 3Wuhan United Imaging Healthcare Co.,Ltd., 430000, Wuhan, China - 4Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, 100191 Beijing, PR China
Introduction: Abnormal foot valgus or varus is typical sign of foot deformity. An accurate assessment of valgus degree is critical for the diagnosis and therapy design. However, the influence of the gender, walking stride frequency, and age on foot valgus remains unclear. This study aims to characterize the valgus degree with the dynamic valgus index, “center of pressure curve – foot midline” index (CFMI), and to quantify the influence of the above factors on this index.
Materials and methods: CFMIs of 94 feet in 47 healthy subjects were obtained with pressure measuring insoles, and were compared with the conventional dynamic and static valgus indexes: center of pressure excursion index (CPEI), coronal plane pressure index (CPPI), relaxed calcaneal stance position and valgus index.
Results: In adults group, valgus of male was greater than that of female. With the stride frequency increasing, valgus of male decreased, while valgus of female increased. Compared with the adults group, children’s CFMI was smaller. Valgus of boy was smaller than that of girl. CPPI had significant correlations with CFMI. CPEI only had significant correlation with midfoot CFMI.
Conclusion: Dynamic valgus indexes had little significant correlations with the static indexes. Taking both static and dynamic indexes into diagnosis may provide a more accurate understanding of the pathology, bone structural deformity or soft tissue imbalance. The findings could help to improve the accuracy in the foot deformity diagnosis, and provide clues for understanding biomechanical pathology.
foot valgus, valgus index, center of pressure, stride frequency.