Compression-induced damage and internal tissue strains are related

Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Building W-hoog 4.11, 5600 MB Eindhoven, The Netherlands.
Journal of Biomechanics (Impact Factor: 2.5). 12/2008; 41(16):3399-404. DOI: 10.1016/j.jbiomech.2008.09.016
Source: PubMed

ABSTRACT Prolonged mechanical loading of soft tissues adjacent to bony prominences can lead to degeneration of muscle tissue, resulting in a condition termed pressure-related deep tissue injury. This type of deep pressure ulcers can develop into a severe wound, associated with problematic healing and a variable prognosis. Limited knowledge of the underlying damage pathways impedes effective preventive strategies and early detection. Traditionally, pressure-induced ischaemia has been thought to be the main aetiological factor for initiating damage. Recent research, however, proposes tissue deformation per se as another candidate for initiating pressure-induced deep tissue injury. In this study, different strain parameters were evaluated on their suitability as a generic predictive indicator for deep tissue injury. With a combined animal-experimental numerical approach, we show that there is a reproducible monotonic increase in damage with increasing maximum shear strain once a strain threshold has been exceeded. This relationship between maximum shear strain and damage seems to reflect an intrinsic muscle property, as it applied across a considerable number of the experiments. This finding confirms that tissue deformation per se is important in the aetiology of deep tissue injury. Using dedicated finite element modeling, a considerable reduction in the inherent biological variation was obtained, leading to the proposal that muscle deformation can prove a generic predictive indicator of damage.

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