PEAK GLUTEAL MUSCLE STRAIN AND STRESS VALUES DURING SITTING ARE GREATER IN PARAPLEGICS THAN IN NORMALS

摘要

Deep tissue injury (DTI) is a severe type of pressure ulcers affecting the viability of muscle tissue under bony prominences first [1]. Most researchers agree that prolonged elevated muscle tissue strains and stresses cause the onset of DTI. We recently showed that internal strain and stress distributions in muscle tissue of individuals can be evaluated by integrating Open-MRI examinations with subject-specific finite element (FE) analyses [2]. However, sub-dermal soft tissue strain and stress data from paraplegic wheelchair users are missing in the literature. Our present goals were therefore (i) to determine the strain and stress distributions in the gluteus muscles and enveloping fat under the ischial tuberosities (IT) of paraplegic wheelchair users during sitting and lying in an Open-MRI, (ii) to compare the paraplegic data to those obtained previously from normal subjects [2], and (iii) to compare between results obtained from paraplegics in the sitting and lying postures, in order to quantify the effect of posture on sub-dermal tissue mechanical conditions, particularly intramuscular shear stress.