title: Biomechanical modeling to prevent ischial pressure ulcers.
abstract: With 300,000 paraplegic persons only in France, ischial pressure ulcers represent a major public health issue. They result from the buttocks׳ soft tissues compression by the bony prominences. Unfortunately, the current clinical techniques, with - in the best case - embedded pressure sensor mats, are insufficient to prevent them because most are due to high internal strains which can occur even with low pressures at the skin surface. Therefore, improving prevention requires using a biomechanical model to estimate internal strains from skin surface pressures. However, the buttocks׳ soft tissues׳ stiffness is still unknown. This paper provides a stiffness sensitivity analysis using a finite element model. Different layers with distinct Neo Hookean materials simulate the skin, fat and muscles. With Young moduli in the range [100-500 kPa], [25-35 kPa], and [80-140 kPa] for the skin, fat, and muscles, respectively, maximum internal strains reach realistic 50 to 60% values. The fat and muscle stiffnesses have an important influence on the strain variations, while skin stiffness is less influent. Simulating different sitting postures and changing the muscle thickness also result in a variation in the internal strains.
authors.affiliation: UJF-Grenoble1/CNRS/TIMC-IMAG UMR 5525, Grenoble F-38041, France. Electronic address: vluboz@imag.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Luboz
authors.affiliation: UJF-Grenoble1/CNRS/TIMC-IMAG UMR 5525, Grenoble F-38041, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Petrizelli
authors.affiliation: TexiSense, Montceau-les-Mines, France. Electronic address: marek.bucki@texisense.com.
authors.forename: Marek
authors.initials: M
authors.lastname: Bucki
authors.affiliation: IDS, Montceau-les-Mines, France, & Univ. Grenoble Alpes, Laboratoire AGIM FRE 3405 CNRS/UJF/UPMF/EPHE, La Tronche, France. Electronic address: b.diot@ids-assistance.com.
authors.forename: Bruno
authors.initials: B
authors.lastname: Diot
authors.affiliation: Univ. Grenoble Alpes, Laboratoire AGIM FRE 3405 CNRS/UJF/UPMF/EPHE, La Tronche, France; Institut Universitaire de France, France. Electronic address: Nicolas.Vuillerme@agim.eu.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vuillerme
authors.affiliation: UJF-Grenoble1/CNRS/TIMC-IMAG UMR 5525, Grenoble F-38041, France. Electronic address: ypayan@imag.fr.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Payan
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D002081:Buttocks / Q000503:physiopathology; D003198:Computer Simulation; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques; D005602:France; D006801:Humans; D007512:Ischium / Q000503:physiopathology*; D008297:Male; D008953:Models, Anatomic; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010264:Paraplegia / Q000150:complications; D011187:Posture / Q000502:physiology; D011312:Pressure; D003668:Pressure Ulcer / Q000517:prevention & control*; D012867:Skin
keywords: Biomechanical model; Pressure ulcer prevention; Spinal cord injury; Stiffness influence