Plantar pressures determinants in mild Hallux Valgus

Abstract

While podobarometric techniques have been applied to the study of pressures in Hallux Valgus (HV), little is known about its clinical and radiological determinants. So, the aim of the present study was to determine the plantar pressure pattern in participants with mild HV, comparing to a control group, and their clinical and anthropometric determinants. Biofoot/IBV^® in-shoe system was used to evaluate 79 participants with mild HV. Computerized measurements of the 1st intermetatarsal angle (IMA) and the hallux abductus angle (HAA) were made on antero-posterior radiographs. The clinical outcome was assessed using the AOFAS score. The dependent baropodometric variables and the independent clinical and anthropometric variables were subjected to a multiple regression analysis. In both groups, the highest average pressure was in the 2nd metatarsal head (MTH). The mean pressure under the Hallux was significantly higher in HV group (controls, 146.5 ± 92.5 kPa; HV, 328.5 ± 113.2 kPa; p < 0.001). An 18.6% of average pressure under the 1st MTH was accounted for pain, first ray alignment and total AOFAS score. Variations of the HAA explained 26.8% of the mean Hallux pressure. Women with mild HV present with pathologically increased pressure under the Hallux, which is caused by the altered alignment of the first ray. Pain and clinical result were associated with the pressure under the 1st MTH and the remaining variables were only moderate predictors of dynamic plantar pressures.

Introduction

Podobarometric techniques applied to the study of pressures in Hallux Valgus (HV) have given mixed results. They have commonly been associated with increased plantar pressures under the central [1] or lateral [2] metatarsal heads (MTHs). Nonetheless, these studies did not differentiate between different degrees of the pathology. Since this is a progressive disorder, mild HV would not have the same load distribution as moderate or severe HV [3]. It remains poorly understood, however, which variables are associated with the specific patterns of plantar pressure in the HV forefoot. Due to the progressive nature of the deformity, we consider it of great interest to study it at its onset. Thus, the purpose of the present study was to determine the magnitude and distribution of forefoot plantar pressure in participants with mild HV, compared with an age-matched healthy control group, and analyze the corresponding clinical and anthropometric determinants.