Ph.D. Defense by Sebastian Laigaard Skals

Sebastian Laigaard Skals will defend his Ph.D. thesis "Musculoskeletal modelling of manual material handling in the supermarket sector"


13.04.2021 kl. 13.00 - 16.00



13.00 Opening by the Moderator Mark de Zee
13.05 PhD lecture by Sebastian Laigaard Skals

13.50 Break
14.00 Questions and comments from the Committee
          Questions and comments from the audience at the Moderator’s discretion
16.00 Conclusion of the session by the Moderator



The Faculty Council has appointed the following adjudication committee to evaluate the thesis and the associated lecture: 


Dr. Prof. Jaap H. van Dieën, VU Amsterdam, Department of Human Movement Sciences, professor of bio-mechanics, van der Boechorststraat 9, head of the Department of Human Movement Sciences, NL-1081BT Amsterdam, Netherlands 

Dr.-Ing., Prof. Sebastian Dendorfer, OTH Regensburg Fakultät Maschinenbau Galgenbergstr. 30, 93053 Regensburg


Dr. Strahinja Dosen, HST, Aalborg Universitet


Dr. Mark de Zee, HST, Aalborg Universitet



Musculoskeletal disorders are the most widespread work-related health problems in the European Union resulting in tremendous societal costs. Low back pain is the most common work-related musculoskeletal disorder and constitute the number one health problem in the world measured in years lived with disability. Manual material handling (MMH) is the most consistently identified occupational risk factor contributing to the development of low back pain. Among the many industries where MMH is common, the supermarket sector has received little attention in the scientific literature, despite musculoskeletal disorders being highly prevalent in the industry. This doctoral thesis employed state-of-the-art methods for inertial-based motion capture and musculoskeletal modelling, as well as surface electromyography, to conduct a comprehensive analysis of the working postures, muscular efforts and biomechanical loads that supermarket workers are subjected to during their daily work. A methodology for musculoskeletal modelling of MMH based on field measurements was developed and evaluated (Paper I), and hereafter used to perform a two-part risk assessment in two supermarkets (Paper II and III). In addition, musculoskeletal models were used to determine the effects of well-known lifting factors on the dynamic loading of the knees, shoulders and lumbar spine in a laboratory setting (Paper IV). Based on the field-analysis, several MMH tasks that may pose a risk for the development of work-related musculoskeletal disorders were identified, while a large proportion of the analysed tasks involved undesirable working postures. Based on the laboratory study, the lifting factors contributing most substantially to the dynamic loading of the involved joints were identified and the results compared to previous modelling studies of MMH as well as the field-based estimates. The thesis was the first to employ state-of-the-art musculoskeletal models for the analysis of work-related MMH on a large scale, highlighting the potential of these models for improving our understanding of the dynamic loading of the involved joints.


Department of Health Science and Technology


Ph.D. Defense take place via Zoom.

Registration Deadline

09.04.2021 kl. 12.00

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