In vitro study design derived from an in vivo lifting task

PAMM, vol. 23

Abstract

Abstract Biomechanical properties of the spinal tissue constituents, especially in the intervertebral disc (IVD), contribute to disability and high costs. The IVD is considered to be one of the main etiologies of chronic low back pain. Changes in the biomechanical properties of the spine, especially in the IVD, are related to multiple factors such as type and duration of loading, recovery periods, osmosis, relaxation, and diffusion processes. To quantify spinal burden in vivo, various dose models have been developed in the context of ergonomics research. In our work both in vivo and in vitro studies were conducted to investigate the effects of loading and rest periods alteration on mechanical properties of the spine. A multibody simulation (MBS) was used to translate the collected motion data from the in vivo study into forces and moments as boundary conditions for the in vitro study. An in vitro spine test rig is used to apply axial compression forces and pure moment loading in flexion/extension direction to spinal segments according to the conditions that have been determined in the MBS. In this article, an approach is presented to coordinate the boundary conditions in vivo and in vitro in order to carry out a holistic investigation. In addition, it is shown why cyclic preconditioning seems to be a more suitable preparation of the samples compared to a constant one in this experimental context.

Authors 9

1. Katharina Brenzel corresponding Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany

2. Laura Johnen Aachen Institute of Industrial Engineering and Ergonomics

   RWTH Aachen University

   Affiliation as printed

   Institute of Industrial Engineering and Ergonomics RWTH Aachen University Aachen Germany

   Institute of Industrial Engineering and Ergonomics, RWTH Aachen University, Aachen, Germany

3. Maximilian Praster Aachen Clinic for Orthopaedics, Trauma and Reconstructive Surgery

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Clinic for Orthopaedics, Trauma and Reconstructive Surgery RWTH Aachen University Hospital Aachen Germany

   Clinic for Orthopaedics, Trauma and Reconstructive Surgery, RWTH Aachen University Hospital, Aachen, Germany

4. Nadja Blomeyer Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany

5. August Weiler Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany

6. Christopher Brandl Aachen Institute of Industrial Engineering and Ergonomics

   Fraunhofer Institute for Communication, Information Processing and Ergonomics · RWTH Aachen University

   Affiliation as printed

   Department of Product and Process Ergonomics Fraunhofer Institute for Communication Information Processing and Ergonomics FKIE Aachen Germany

   Institute of Industrial Engineering and Ergonomics RWTH Aachen University Aachen Germany

   Department of Product and Process Ergonomics, Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE, Aachen, Germany

   Institute of Industrial Engineering and Ergonomics, RWTH Aachen University, Aachen, Germany

7. Heiko Topol Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany

8. Marcus Stoffel Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany

9. Bernd A. Markert Aachen Institute of General Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of General Mechanics RWTH Aachen University Aachen Germany

   Institute of General Mechanics, RWTH Aachen University, Aachen, Germany