Project Details
Projekt
SP6 Decoding Spinal Dysfunction: Causal Mechanisms of Muscle and Compensatory Adaptations through Functional Animal and Musculoskeletal Modeling
Subject Area
Orthopaedics, Traumatology, Reconstructive Surgery
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 439742772
The aim of the first funding period of FOR 5177 was to systematically investigate the mechanical influences on tissue adaptation and degeneration following surgical interventions to the spine, using a large animal model combined with numerical simulations. Contrary to the widely accepted assumptions from in vitro studies, neither compensatory hypermobility in adjacent segments after fusion nor persistent hypermobility of the operated segment after nucleotomy could be confirmed in vivo. Instead, movement restrictions were observed, indicating spinal stabilization and suggesting effective neuromuscular adaptations. Complementary finite element analyses demonstrated that local changes in mechanical loading can induce targeted osseous adaptations, and that dynamic loading scenarios promote the restoration of segmental stability. Furthermore, activity level was shown to have a significant impact on the dynamic movement patterns of the spine. Using specially developed AI-supported video analysis methods for large animals, we revealed functional relationships between limb function and spinal motion, thus demonstrating the integrative neuromuscular control underlying spinal movement. Building on these insights, the second funding period focuses on the role of muscle function as a central driver of spinal adaptation processes. The core objective is to analyze causal mechanisms by which muscle dysfunction induces functional alterations in spinal mechanics. For this purpose, we employ a functional large animal model that mimics muscular changes observed in chronic low back pain by inducing selective muscle inactivity through targeted neurotomy. An integrative methodological approach combines functional in vivo assessments (including EMG, kinematics, and behavioral analyses), ex vivo structural evaluations, and in silico simulations to investigate the interplay between muscle (in)activity, mechanical loading, structural changes, and pain mechanisms. The central hypothesis posits a self-reinforcing vicious cycle: muscle dysfunction leads to mechanical overload, which triggers a neuroinflammatory response that promotes pain chronification - thereby further exacerbating muscle dysfunction. This project makes a crucial contribution to the overall initiative by systematically elucidating neuromuscular mechanisms in chronic low back pain and establishing a methodological foundation for improved diagnostics.
DFG Programme
Research Units
Subproject of
FOR 5177:
The Dynamics of the Spine: Mechanics, Morphology and Motion towards a comprehensive Diagnosis of Low Back Pain
Co-Investigators
Professor Dr.-Ing. Georg Duda; Professor Dr. Hendrik Schmidt
