3D Weight-Bearing CT Imaging Analysis of Foot Mechanics: Bridging High Heels and Hallux Valgus
Authors: Carvalho Kepler A.M. , Mann Tania Szejnfeld , Fayed Aly , Talaski Grayson M. , Luo Emily Joan , Acker Antoine , Mansur Nacime Salomao Barbachan , Kaplan Jonathan , Chrea Bopha , de Cesar Netto Cesar 
Published: April 2024

Introduction/Purpose: Evidence in the literature suggests the negative effects of using High Heels (HH), becoming a challenge for clinicians and researchers since they are welcomed by women worldwide, mainly due to the subjective power of attractiveness given to them. Although some people blame HH as one of the causes of Hallux Valgus (HV), until now, there are no studies in the literature that effectively prove a cause-effect relationship between HH and HV. The objectives of this study are: (1) to analyze whether the increase in heel height can lead to HV and (2) to evaluate whether HV can increase in severity with increasing heels. We hypothesized that an increase in heel height could cause and increase the severity of HV deformity. Methods: Comparative cross-sectional study. Forty-one feet from twenty-one participants (11 males and 10 females, aged 30.8 ± 8.9 years, and with Body Mass Index 25.5 ± 2.0 m kg2) were recruited. HH shoes were designed for this study with three heights for each participant: 3, 6, and 9 cm. The inclusion criteria were: no regular wearing of heels. The exclusion criteria were: Hallux Valgus diagnosis and/or any orthopedic conditions that affect the Foot and Ankle joints. Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), First-Metatarsal Phalangeal Angle, 1st-to-5th Intermetatarsal Angle, First Tarsometatarsal Angle (axial), Second tarsometatarsal angle (axial), Hindfoot Moment Arm (HMA) (mm), Saltzman 45 angle and, Foot Ankle Offset (FAO) were measurement using semiautomated software analysis. Multiple comparisons were performed (Bonferroni's for normal distributions and Wilcoxon test for no normal distributions) when there was a main effect on an outcome (p < 0.05). Results: With the increase in HH, we noticed a progressive increase in HVA (p < 0.001), IMA (p < 0.001), First-Metatarsal Phalangeal Angle (p < 0.001), First Tarsometatarsal Angle (axial) (p < 0.001), and the Second tarsometatarsal angle (axial) (p < 0.001). The Hindfoot Moment Arm (HMA) (mm), Saltzman 45 angle, and Foot Ankle Offset (FAO) had hindfoot varization behavior. When we stratified the groups and compared them, we noticed that an increase of 3 cm in heels slightly increased HVA and IMA (p > 0.05). However, heel increases above 6 cm significantly increased HVA and IMA (p > 0.001). Based on Coughlin's classification, a 3 cm heel increase promoted a mild HV and increases above 6 cm caused a moderate HV. Conclusion: Based on data from our study with patients without Hallux Valgus through analysis with WBCT versus high heels, we conclude that increasing heel height can lead to Hallux Valgus and can progressively increase the severity with increasing high heels. High heels above 6 cm can lead to moderate Hallux Valgus. These findings may be an essential step toward a better understanding of the effects of increasing high heels on Hallux Valgus pathology.