Identification of Foot Pathologies Based on Plantar Pressure Asymmetry

Abstract

Foot pathologies can negatively influence foot function, consequently impairing gait during daily activity, and severely impacting an individual's quality of life. These pathologies are often painful and correspond with high or abnormal plantar pressure, which can result in asymmetry in the pressure distribution between the two feet. There is currently no general consensus on the presence of asymmetry in able-bodied gait, and plantar pressure analysis during gait is in dire need of a standardized method to quantify asymmetry. This paper investigates the use of plantar pressure asymmetry for pathological gait diagnosis. The results of this study involving plantar pressure analysis in fifty one participants (31 healthy and 20 with foot pathologies) support the presence of plantar pressure asymmetry in normal gait. A higher level of asymmetry was detected at the majority of the regions in the feet of the pathological population, including statistically significant differences in the plantar pressure asymmetry in two regions of the foot, metatarsophalangeal joint 3 (MPJ3) and the lateral heel. Quantification of plantar pressure asymmetry may prove to be useful for the identification and diagnosis of various foot pathologies.

Keywords: foot pathology; gait symmetry; plantar pressure.

Figure 1

An example of in-shoe plantar pressure measurement during the major phases and events of a full gait cycle (right heel strike to right heel strike). HS = heel strike, FF = foot flat, MSt = midstance, HO = heel off, TO = toe off, IS = initial swing, MSw = midswing.

Figure 2

Mask of the 10 anatomical regions of interest in the foot. The magnified area highlights the joints at which pressure values were extracted from regions 1, 3–7.

Figure 3

The 2D and 3D representation of in-shoe plantar pressure distribution in a healthy control during the stance phase of the gait cycle, from HS to HO, and the averaged pressure distribution from four stances.

Figure 4

The 2D and 3D representation of an in-shoe plantar pressure distribution resulting from metatarsalgia in the pathological foot during the stance phase of the gait cycle, from HS to HO, and the averaged pressure distribution from four stances.

Figure 5

The 2D and 3D representation of an in-shoe plantar pressure distribution resulting from subtalar joint and heel pain in the pathological foot during the stance phase of the gait cycle, from HS to HO, and the averaged pressure distribution from four stances.