Simulation; Modeling; AIS; Biomechanics; OpenSim; Activities of daily living; Spinal deformity
Schmid Stefan, Burkhart Katelyn A., Allaire Brett T., Grindle Daniel, Bassani Tito, Galbusera Fabio, Anderson Dennis E. (2020), Spinal Compressive Forces in Adolescent Idiopathic Scoliosis With and Without Carrying Loads: A Musculoskeletal Modeling Study, in Frontiers in Bioengineering and Biotechnology
, 8, 159.
Schmid Stefan, Burkhart Katelyn A., Allaire Brett T., Grindle Daniel, Anderson Dennis E. (2019), Musculoskeletal full-body models including a detailed thoracolumbar spine for children and adolescents aged 6-18 years, in Journal of Biomechanics
Given the poorly understood pathogenesis of adolescent idiopathic scoliosis (AIS), a complex three-dimensional deformity of the spine, as well as the controversial evidence on conservative treatment methods such as scoliosis-specific exercises (SSEs), this research project aims at the identification of complex biomechanical parameters that might contribute to a better understanding of the pathomechanics of curve progression using muscle-driven simulations of AIS patients during different functional movements.In the first part of my project, an OpenSim-based multibody thoracolumbar musculoskeletal spine model, previously developed and validated in the Bouxsein laboratory for adults, will be adapted in order to enable predictions of segmental loading and individual muscle forces in healthy adolescents. To allow simulations in patients with AIS, the generic healthy-adolescent-model will then be further adapted by incorporating spinal deformation characteristics derived from simultaneously captured and spatially paired AP and lateral X-ray images (EOS scan). Due to a lack of in vivo measures of spinal loading in adolescents with and without AIS, a validation of the adapted models will be performed based on available MRI-derived deformation measures of the axially loaded spine as well as on the paravertebral myoelectric activity of different static body positions.In the second part of my project, segmental loading and individual muscle forces of the AIS spine during functional activities such as standing, sitting, bending forward/backward, chair rising, lifting an object, vertical jumping and walking/running will be investigated by driving subject-specific AIS- and generic healthy-adolescent-models with real motion capture data obtained from 10 patients with AIS as well as 10 healthy adolescents. Participants will be invited to the motion analysis laboratory at Beth Israel Deaconess Medical Center & Harvard Medical School (AIS patients within one week of a scheduled routine EOS scan) and assessed using a Vicon motion analysis system while performing the aforementioned functional activities. Subject-specific AIS-models will be created by incorporating the individual EOS scan-derived spinal deformation characteristics into the generic healthy-adolescent-model. Both subject-specific AIS- and generic healthy-adolescent-models will then be used together with the experimentally acquired data to conduct dynamic simulations, which include the calculation of segmental loading as well as muscle excitations and muscle forces. Continuous model output data will be parameterized appropriately and group comparisons will be conducted using independent samples t-tests. The sample size of 10 subjects per group was derived from effect size estimates found by posing the existing adult-model with appropriate lateral curvatures.The outcomes of this study will contribute to a better understanding of the pathomechanics of curve progression in AIS patients, which can be directly used by clinicians to adapt current treatment approaches such as SSEs. Moreover, the outcomes of this project will form a solid methodological basis for future investigations on the functional biomechanics of patients with structural deformities of the spine. Research groups around the world can use this method to evaluate and further develop treatment approaches as well as preventive strategies in patients with spinal pathologies.