Deformations, mechanical strains and stresses across the different hierarchical scales in weight-bearing soft tissues

Using ultrasound elastography to monitor human soft tissue behaviour during prolonged loading: A clinical explorative study

“…Based on the current state of the science, this finding is difficult to interpret. In DTI development it is widely acknowledged that muscle cell necrosis (rhabdomyolosis) is associated with increased stiffness [22,24] based on a positive-feedback mechanism in which elevated stress of injured muscle tissue spreads and increases the potential for cell necrosis in muscle tissue [25]. However, the opposite was observed.…”

“…Recently US elastography was also proposed as a new diagnostic approach for early PU detection [22,23]. Early stage PU development is associated with increased tissue stiffness [24,25] e changes of elastic properties assumed to be measureable. Therefore, the aim of this study was to investigate whether US elastography is able to measure potential changes in dermal and subdermal tissue stiffness during prolonged loading in healthy volunteers.…”

Evaluation of Repositioning in Pressure Ulcer Prevention

“…This is the most established theory of pressure ulcer aetiology whereby mechanical loading leads to tissue breakdown. Other theories have been proposed, including impaired lymphatic function (Reddy et al, 1981), ischemiareperfusion injury (Peirce et al, 2000), and, more recently, sustained deformations of cells causing cell-membrane leakage (Leopold & Gefen, 2013;Shoham & Gefen, 2012). Among these theories, it is suggested that cell deformation is mainly involved over short periods (within minutes) with highpressure exposure, while ischemia increases over time, such as several hours, and becomes the dominant factor for prolonged pressure exposure (Stekelenburg et al, 2008).…”

Preventing pressure ulcers by assessment of the microcirculation in tissue exposed to pressure

“…Four main factors are believed to be involved, including ischemia (Shilo and Gefen, 2012), cell deformation (Shoham and Gefen, 2012), impaired lymphatic drainage (Kasuya et al, 2014), and reperfusion injury (Jiang et al, 2011). The ischemia theory was first developed by Kosiak (1961) and then expanded upon by Witkowski andParish (Kosiak, 1961, Witkowski andParish, 1982).…”