Print Email Facebook Twitter Sensory contributions to stabilization of trunk posture in the sagittal plane Title Sensory contributions to stabilization of trunk posture in the sagittal plane Author van Dieën, Jaap H. (Vrije Universiteit Amsterdam) van Drunen, P. (TU Delft Biomechatronics & Human-Machine Control) Happee, R. (TU Delft Intelligent Vehicles) Date 2017 Abstract Trunk stabilization is required to control posture and movement during daily activities. Various sensory modalities, such as muscle spindles, Golgi tendon organs and the vestibular system, might contribute to trunk stabilization and our aim was to assess the contribution of these modalities to trunk stabilization. In 35 healthy subjects, upper-body sway was evoked by continuous unpredictable, force-controlled perturbations to the trunk in the anterior direction. Subjects were instructed to either ‘maximally resist the perturbation’ or to ‘relax but remain upright’ with eyes closed. Frequency response functions (FRFs) of admittance, the amount of movement per unit of force applied, and reflexes, the modulation of trunk extensor activity per unit of trunk displacement, were obtained. To these FRFs, we fitted physiological models, to estimate intrinsic trunk stiffness and damping, as well as feedback gains and delays. The different model versions were compared to assess which feedback loops contribute to trunk stabilization. Intrinsic stiffness and damping and muscle spindle (short-delay) feedback alone were sufficient to accurately describe trunk stabilization, but only with unrealistically low reflex delays. Addition of muscle spindle acceleration feedback or inhibitory Golgi tendon organ feedback yielded realistic delays and improved the model fit, with a significantly better model fit with acceleration feedback. Addition of vestibular feedback did not improve the model fit. In conclusion, muscle spindle feedback and intrinsic mechanical properties are sufficient to describe trunk stabilization in the sagittal plane under small mechanical perturbations, provided that muscle spindles encode acceleration in addition to velocity and position information. Subject SpinePostural controlSystem identificationFeedback To reference this document use: http://resolver.tudelft.nl/uuid:1e75c9a4-1a81-4f0b-b9e1-d53f626939ef DOI https://doi.org/10.1016/j.jbiomech.2017.07.016 Embargo date 2018-08-05 ISSN 0021-9290 Source Journal of Biomechanics, 70 (2018), 219-227 Bibliographical note Accepted Author Manuscript Part of collection Institutional Repository Document type journal article Rights © 2017 Jaap H. van Dieën, P. van Drunen, R. Happee Files PDF vanDie_n_vanDrunen_Happee ... run.._.pdf 1.44 MB Close viewer /islandora/object/uuid:1e75c9a4-1a81-4f0b-b9e1-d53f626939ef/datastream/OBJ/view