Print Email Facebook Twitter Quantifying Proprioceptive Reflexes During Position Control of the Human Arm Title Quantifying Proprioceptive Reflexes During Position Control of the Human Arm Author Schouten, A.C. De Vlugt, E. Van Hilten, J.J. Van der Helm, F.C. Faculty Mechanical, Maritime and Materials Engineering Department Biomechanical Engineering Date 2008-01-01 Abstract This study aimed to analyse the dynamic properties of the muscle spindle feedback system of shoulder muscles during a posture task. External continuous force disturbances were applied at the hand while subjects had to minimize their hand displacements. The results were analysed using two frequency response functions (FRFs) from which the model parameters were derived, being 1) the mechanical admittance and 2) the reflexive impedance. These FRFs were analysed by a neuromusculoskeletal model that implicitly separates the reflexive feedback properties (position, velocity and acceleration feedback gains) from intrinsic muscle visco-elasticity. The results show substantial changes in estimated reflex gains under conditions of variable bandwidth of the applied force disturbance or variable degrees of external damping. Position and velocity feedback gains were relatively larger when the force disturbance contained only low frequencies. With increasing damping of the environment, acceleration feedback gain decreased, velocity feedback gain remained almost constant and position feedback gain increased. It is concluded that under the aforementioned circumstances, the reflex system increases its gains to maximize the mechanical resistance to external force disturbances while preserving sufficient stability. Subject arm admittanceelectromyographyidentificationproprioceptive reflexesreflexive impedance To reference this document use: http://resolver.tudelft.nl/uuid:5fef4b7a-840b-429f-932e-cb3e81feda2e Publisher IEEE ISSN 0018-9294 Source IEEE Transactions on Biomedical Engineering, 55 (1), 2008 Part of collection Institutional Repository Document type journal article Rights (c) 2008 The Author(s) ; IEEE Files PDF Schouten_2008.pdf 1.22 MB Close viewer /islandora/object/uuid:5fef4b7a-840b-429f-932e-cb3e81feda2e/datastream/OBJ/view