A Quasi-Linear, Viscoelastic, Structural Model of the Plantar Soft Tissue With Frequency-Sensitive Damping Properties
- 1 December 2004
- journal article
- research article
- Published by ASME International in Journal of Biomechanical Engineering
- Vol. 126 (6), 831-837
- https://doi.org/10.1115/1.1824133
Abstract
Little is known about the structural properties of plantar soft-tissue areas other than the heel; nor is it known whether the structural properties vary depending on location. Furthermore, although the quasi-linear viscoelastic (QLV) theory has been used to model many soft-tissue types, it has not been employed to model the plantar soft tissue. The structural properties of the plantar soft tissue were quantified via stress relaxation experiments at seven regions (subcalcaneal, five submetatarsal, and subhallucal) across eight cadaveric feet. The cadaveric feet were 36.9 +/- 17.4 (mean +/- S.D.) years of age, all free from vascular diseases and orthopedics disorders. All tests were performed at a constant environmental temperature of 35 degrees C. Stress relaxation experiments were performed; different loads were employed for different areas based on normative gait data. A modification of the relaxation spectrum employed within the QLV theory allowed for the inclusion of frequency-sensitive relaxation properties in addition to nonlinear elastic behavior. The tissue demonstrated frequency-dependent damping properties that made the QLV theory ill suited to model the relaxation. There was a significant difference between the elastic structural properties (A) of the subcalcaneal tissue and all other areas (p = 0.004), and a trend (p = 0.067) for the fifth submetatarsal to have less viscous damping (c1) than the subhallucal, or first, second, or third submetatarsal areas. Thus, the data demonstrate that the structural properties of the foot can vary across regions, but careful consideration must be given to the applied loads and the manner in which the loads were applied.This publication has 25 references indexed in Scilit:
- Material properties of the human calcaneal fat pad in compression: experiment and theoryJournal of Biomechanics, 2002
- Altered heel‐pad mechanical properties in patients with Type 2 diabetes mellitusDiabetic Medicine, 2000
- The mechanical properties of the heel pad in elderly adultsEuropean Journal of Applied Physiology, 1996
- The mechanical properties of the human heel pad: A paradox resolvedJournal of Biomechanics, 1995
- Histology and Histomorphometric Analysis of the Normal and Atrophic Heel Fat PadFoot & Ankle International, 1995
- Human subcutaneous adipose tissue shows site-specific differences in fatty acid compositionThe American Journal of Clinical Nutrition, 1994
- In Vivo Examination of the Dynamic Properties of the Human Heel PadInternational Journal of Sports Medicine, 1993
- Investigations into the Fat Pads of the Sole of the Foot: Anatomy and HistologyFoot & Ankle, 1992
- Chronic Peroneus Brevis Tendon LesionsFoot & Ankle, 1989
- Sonography of the Sole of the FootInvestigative Radiology, 1986