The Stress–strain state in the pelvis during sit-to-stand transfer

Žnidaršič, Urban (author), Žerovnik, Andrej (author), Tomaževič, Matevž (author), Kunc, Robert (author)

To achieve early mobilization of patients with unstable pelvic fractures, the osteosynthesis methods used must withstand the loads in the pelvis during everyday movements. There is currently no predictive tool to assess how suitable these methods are for this purpose. The development of such a tool requires an understanding of the effects of joint and muscle loads on the structural behavior of the pelvis during movement. To further this cause, the stress–strain state of the pelvis during a sit-to-stand transfer of a healthy adult male was analyzed. Muscle and joint reaction forces during the motion were predicted using a rigid-body musculoskeletal model. These loads were then utilized in the first-ever dynamic structural analysis of the pelvis during a sit-to-stand transfer using the finite element method. Several similarities in stress distributions during sit-to-stand transfer, gait, and standing were identified by comparing the finite element analysis results with literature. The common areas of increased stress between the three motions are the acetabular notch, the superior edge of the obturator foramen, the attachments of the gluteus maximus on the ilium, and the lesser sciatic notch. The results also provide important insights into global behavior of the pelvic ring and indicate the locations of concentrated stress during sit-to-stand transfer.

• Language: English
• Keywords: pelvis, structural analysis, sit-to-stand transfer, finite element method, inverse dynamics, muscle forces
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 17 str.
• Numbering: Vol. 12, issue 12, [article no.] 1328
• PID: 20.500.12556/RUL-179120
• UDC: 616.718.19:658.5
• ISSN on article: 2306-5354
• DOI: 10.3390/bioengineering12121328
• COBISS.SI-ID: 267440131
• Publication date in RUL: 05.02.2026

Record is a part of a journal

• Title: Bioengineering
• Shortened title: Bioengineering
• Publisher: MDPI AG
• ISSN: 2306-5354
• COBISS.SI-ID: 523002649

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: medenica, strukturna analiza, vstajanje iz sedečega položaja, metoda končnih elementov, inverzna dinamika, sile mišic

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0109
• Name: Modeliranje v tehniki in medicini