Document Type : Full Research Paper

Authors

• Giti Torkamaan ¹
• Ali Fallah ²
• Mahmoud Mofid ³
• Sedighe Ghiasi ⁴
• Ghadam Ali Talebi ⁵

¹ Associate Professor, Physical Therapy Department, Medical Sciences School, Tarbiat Modares University

² Assistant Professor, Biomedical Engineering School, Amirkabir University

³ Instructor, Anatomy Department, Medical School, Baghiyatallah University of Medical Sciences

⁴ MSc Graduated, Physical Therapy Department, Medical Sciences School, Tarbiat Modares University

⁵ Assistant Professor, Physical Therapy Department, Rehabilitation School, Tabriz University of Medical Sciences

Abstract

In this study 22 male Guinea Pigs, 4-6 months old, weighting 400-450 g were used. A computer controlled indentor system was used to apply a controlled pressure. The applied pressure was 291 mmHg for 3 hours over the trochanter region of animal hind limb. The animals were divided in three groups; in group 1, pressure was applied 3 hours continuously, in group 2, pressure was applied 90 minutes at two days and in group 3, Pressure was applied in two cycles of 90 minutes with 15 minutes rest between them. To study the biomechanical and histological changes, tissue was removed 7 days after pressure application. Uniaxial tensile test was performed at a deformation rate of 20 mm/min. In this test, the contralateral site on the experimental animal served as intra-animal control. Tissue biopsy was taken and stained with H&E and Trichorome for histological examination. Continuous pressure induced muscle necrosis. Also ultimate stress, stiffness, ultimate strain and area under the load-deformation curve decreased significantly. These results suggest that application of continuous pressure is the major cause of ischemia and necrosis of soft tissue.

Keywords

• External Pressure
• Ischemia
• Skin
• Biomechanical Characteristics
• Tensile strength

Main Subjects

• Tissue Engineering