Characterization of gait using plantar force transfer trajectory in individuals with hallux valgus deformity

Hallux Valgus (HV) is the most common fore-foot deformity, which causes foot pain and limited motion that are encountered in podiatric and orthopedic practices. The purpose of this study is to develop a reliable pattern recognition method to identify the presence of HV based on plantar force measurements.

Forces at five discrete metatarsal regions are measured at discrete time intervals under the right foot. Under this method, it is hypothesized that force measurement at a given time interval is related to the forces at a previous time interval by using Markovian transition matrix (T matrix). Thirty volunteers' (10 with HV, 10 without HV and 10 with un-diagnosed HV) condition were examined. The use of a Markovian transition matrix for gait characterization is novel. T matrices of all the participants were obtained and compared using means and standard deviations of each of the matrix elements. The comparison was undertaken using a new measure called the "Diagnostic Ratio" (DR). Independent Sample T-test was performed on the T matrix elements.

A significant difference was observed between the HV and non-HV groups. HV volunteers were recognized from the dispersion of the T matrices' elements. For volunteers with un-diagnosed condition exhibiting borderline DR may be interpreted as them being prone to HV.

Comparison of transfer matrices using means and standard deviations of the HV and non-HV groups revealed that a DR of higher than 40% could suggest having an HV condition for five volunteers of the un-diagnosed group and two were found to be prone to getting the condition.