An investigation of the relationship between plantar pressure distribution and the morphologic and mechanic properties of the intrinsic foot muscles and plantar fascia

Abstract

BackgroundThe purpose of this study was to investigate the relationship between plantar pressure distribution and the stiffness, thickness, and cross-sectional area of the plantar fascia (PF) and abductor hallucis (AbH), flexor hallucis brevis (FHB), and flexor digitorum brevis (FDB) muscles. MethodsThe present study included a total of 41 healthy females between the ages of 20 and 34 years. Plantar pressure during static standing position was measured using a pedobarography system (MatScan, Tekscan, Inc., South Boston, Massachusetts, USA). Peak pressure, mean pressure, maximum force (Max-F), contact area (Con-A), pressure time integral, and force time integral (FTI) were measured. The thickness, cross-sectional area and stiffness of the intrinsic foot muscles and PF were measured using an ACUSON S3000 Ultrasound System and a 9L4 probe (4–9 MHz) (Siemens Medical Solution, Mountain View, CA, USA). Shear Wave Velocity (SWV) of the intrinsic foot muscles and PF was measured using a customized software program (Virtual Touch Imaging and Quantification; Siemens Medical Solution). ResultsCon-A had a moderate correlation with the thickness and cross-sectional area of PF, AbH, FHB, and FDB. A fair to moderate correlation was found between heel Max-F and the thickness and cross-sectional area of PF, AbH, FHB, and FDB. There is no significant correlation between the SWV of the assessed tissues and plantar pressure distribution parameters. Body mass and BMI had a fair to good correlation with Mean-P, Con-A, heel Max-F, midfoot Max-F, metatarsal Max-F, FTI, thickness, and cross-sectional area of the PF and assessed muscles SignificanceThe results suggest that abnormal force, contact area, and higher body mass may cause hypertrophy of the PF and foot intrinsic muscles.