Perfusion, Stance and Plantar Pressure Asymmetries on the Human Foot in the Absence of Disease—A Pilot Study

Luis Monteiro Rodrigues,Sérgio Loureiro Nuno,Tiago Granja,João Gregório,Tiago Atalaia,Margarida Esteves Florindo

doi:10.3390/sym14030441

Abstract

Physiological perfusion asymmetries in the lower limb are known, although poorly understood, as are asymmetries reported in plantar pressure and stance. This preliminary study aims to explore potential relationships between perfusion and pressure variables in humans. A convenience sample of eight healthy individuals (25.25 ± 5.37 years old) of both sexes, was selected. Chosen variables were perfusion, plantar pressure, and stance. Perfusion was measured in both feet by laser Doppler flowmetry (LDF) and polarized light spectroscopy (PSp), and plantar pressure and stance obtained by a pressure plate. These were measured in baseline (Phase I) in a repeated squatting (Phase II), and in recovery (Phase III). A 95% confidence interval was adopted. Intraindividual significant perfusion asymmetries between both feet were detected by LDF in Phase I. These disappeared in Phase II and returned in Phase III. PSp did not detect any asymmetries. Plantar pressure was also asymmetric and differently distributed along both feet with no statistical significance except in the hindfoot. Significant correlations were found between BMI and mean Plantar Pressure in Phase I and Phase III, and an inverse correlation between LDF perfusion and Plantar Pressure in Phase I. These results seem to suggest an interesting direction for exploration and study of these asymmetries in the absence of disease.

Highlights

Peripheral arterial disease and arterial blood pressure differences in the arm and leg were identified and described in the mid-nineteenth century [1,2] but only with modern imaging technology has our attention been drawn to lower limb circulatory asymmetries in the absence of disease [3,4,5]
Physiological perfusion asymmetries may be defined as differences in baseline perfusion between paired limbs
That is, “the inability to produce a force of contraction that is equal in both lower extremities” [13], gained particular relevance in sports physiology related to strength and training conditioning [14,15]

Summary

Introduction

Peripheral arterial disease and arterial blood pressure differences in the arm and leg were identified and described in the mid-nineteenth century [1,2] but only with modern imaging technology has our attention been drawn to lower limb circulatory asymmetries in the absence of disease [3,4,5]. Physiological perfusion asymmetries may be defined as differences in baseline perfusion between paired limbs. The significance of these asymmetries remains unknown. That is, “the inability to produce a force of contraction that is equal in both lower extremities” [13], gained particular relevance in sports physiology related to strength and training conditioning [14,15]. A significant inverse relationship between force asymmetry and muscular performance was reported [17,18], and interlimb asymmetries have been suggested to involve higher non-contact injury risk likely accentuated by the sporting activity [19,20]. The distal activation of both limbs, no matter the asymmetries, seems to demand equivalent perfusion levels even for common activities such as bipedal walking [21,22]

Methods

Results

Conclusion