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Poor motor function is associated with reduced sensory processing after stroke

Campfens, S.F. (author), Zandvliet, S.B. (author), Meskers, C.G.M. (author), Schouten, A.C. (author), Van Putten, M.J.A.M. (author), Van der Kooij, H. (author)

Abstract The possibility to regain motor function after stroke depends on the intactness of motor and sensory pathways. In this study, we evaluated afferent sensory pathway information transfer and processing after stroke with the coherence between cortical activity and a position perturbation (position-cortical coherence, PCC). Eleven subacute...

journal article

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Quantifying Proprioceptive Reflexes During Position Control of the Human Arm

Schouten, A.C. (author), De Vlugt, E. (author), Van Hilten, J.J. (author), Van der Helm, F.C. (author)

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...

journal article 2008

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Design of Perturbation Signals for the Estimation of Proprioceptive Reflexes

Schouten, A.C. (author), De Vlugt, E. (author), Van der Helm, F.C.T. (author)

This study aimed to identify the functional contribution of reflexes to human motor control during posture maintenance. Continuous random force disturbances were applied at the hand while the subjects were instructed to minimize the deviation resulting from the force disturbances. The results were analyzed in the frequency domain with frequency...

journal article 2008

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The monosynaptic Ia afferent pathway can largely explain the stretch duration effect of the long latency M2 response

Schuurmans, J. (author), De Vlugt, E. (author), Schouten, A.C. (author), Meskers, C.G. (author), De Groot, J.H. (author), Van der Helm, F.C.T. (author)

Sudden stretch of active muscle typically results in two characteristic electromyographic responses: the short latency M1 and the long latency M2. The M1 response originates from the monosynaptic Ia afferent reflex pathway. The M2 response is less well understood and is likely a compound response to different afferent inputs mediated by spinal...

journal article 2009

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Sensory Weighting of Force and Position Feedback in Human Motor Control Tasks

Mugge, W. (author), Schuurmans, J. (author), Schouten, A.C. (author), Van der Helm, F.C.T. (author)

In daily life humans integrate force and position feedback from mechanoreceptors, proprioception, and vision. With handling relatively soft, elastic objects, force and position are related and can be integrated to improve the accuracy of an estimate of either one. Sensory weighting between different sensory systems (e.g., vision and...

journal article 2009

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Muscle weakness and lack of reflex gain adaptation predominate during post-stroke posture control of the wrist

Meskers, C.G.M. (author), Schouten, A.C. (author), De Groot, J.H. (author), De Vlugt, E. (author), Van Hilten, B.J.J. (author), Van der Helm, F.C.T. (author), Arendzen, H.J.H. (author)

Background Instead of hyper-reflexia as sole paradigm, post-stroke movement disorders are currently considered the result of a complex interplay between neuronal and muscular properties, modified by level of activity. We used a closed loop system identification technique to quantify individual contributors to wrist joint stiffness during an...

journal article 2009

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A rigorous model of reflex function indicates that position and force feedback are flexibly tuned to position and force tasks

Mugge, W. (author), Abbink, D.A. (author), Schouten, A.C. (author), Dewald, J.P.A. (author), Van der Helm, F.C.T. (author)

This study aims to quantify the separate contributions of muscle force feedback, muscle spindle activity and co-contraction to the performance of voluntary tasks (‘‘reduce the influence of perturbations on maintained force or position’’). Most human motion control studies either isolate only one contributor, or assume that relevant reflexive...

journal article 2009

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Tizanidine does not affect the linear relation of stretch duration to the long latency M2 response of m. flexor carpi radialis

Meskers, C.G.M. (author), Schouten, A.C. (author), Rich, M.M.L. (author), De Groot, J.H. (author), Schuurmans, J. (author), Arendzen, J.H. (author)

The long latency M2 electromyographic response of a suddenly stretched active muscle is stretch duration dependent of which the nature is unclear. We investigated the inXuence of the group II aVerent blocker tizanidine on M2 response characteristics of the m. Xexor carpi radialis (FCR). M2 response magnitude and eliciting probability in a group...

journal article 2009

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The intermuscular 3–7 Hz drive is not affected by distal proprioceptive input in myoclonus-dystonia

Van der Meer, J.N. (author), Schouten, A.C. (author), Bour, L.J. (author), De Vlugt, E. (author), Van Rootselaar, A.F. (author), Van der Helm, F.C.T. (author), Tijssen, M.A.J. (author)

In dystonia, both sensory malfunctioning and an abnormal intermuscular low-frequency drive of 3–7 Hz have been found, although cause and eVect are unknown. It is hypothesized that sensory processing is primarily disturbed and induces this drive. Accordingly, experimenter-controlled sensory input should be able to inXuence the frequency of the...

journal article 2010

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Relating reflex gain modulation in posture control to underlying neural network properties using a neuromusculoskeletal model

Schuurmans, J. (author), Van der Helm, F.C.T. (author), Schouten, A.C. (author)

During posture control, reflexive feedback allows humans to efficiently compensate for unpredictable mechanical disturbances. Although reflexes are involuntary, humans can adapt their reflexive settings to the characteristics of the disturbances. Reflex modulation is commonly studied by determining reflex gains: a set of parameters that quantify...

journal article 2010

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Fixed Dystonia in Complex Regional Pain Syndrome: A Descriptive and Computational Modeling Approach

Munts, A.G. (author), Mugge, W. (author), Meurs, T.S. (author), Schouten, A.C. (author), Marinus, J. (author), Lorimer Moseley, G. (author), Van der Helm, F.C.T. (author), Van Hilten, J.J. (author)

Background: Complex regional pain syndrome (CRPS) may occur after trauma, usually to one limb, and is characterized by pain and disturbed blood flow, temperature regulation and motor control. Approximately 25% of cases develop fixed dystonia. Involvement of dysfunctional GABAergic interneurons has been suggested, however the mechanisms that...

journal article 2011

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EMG feedback tasks reduce reflexive stiffness during force and position perturbations

Forbes, P.A. (author), Happee, R. (author), Van der Helm, F.C.T. (author), Schouten, A.C. (author)

Force and position perturbations are widely applied to identify muscular and reflexive contributions to posture maintenance of the arm. Both task instruction (force vs. position) and the inherently linked perturbation type (i.e., force perturbations-position task and position perturbations-force tasks) affect these contributions and their mutual...

journal article 2011

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Identification of the contribution of the ankle and hip joints to multi-segmental balance control

Boonstra, T.A. (author), Schouten, A.C. (author), Van der Kooij, H. (author)

Background Human stance involves multiple segments, including the legs and trunk, and requires coordinated actions of both. A novel method was developed that reliably estimates the contribution of the left and right leg (i.e., the ankle and hip joints) to the balance control of individual subjects. Methods The method was evaluated using...

journal article 2013

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Integration of Sensory Force Feedback Is Disturbed in CRPS-Related Dystonia

Mugge, W. (author), Van der Helm, F.C.T. (author), Schouten, A.C. (author)

Complex regional pain syndrome (CRPS) is characterized by pain and disturbed blood flow, temperature regulation and motor control. Approximately 25% of cases develop fixed dystonia. The origin of this movement disorder is poorly understood, although recent insights suggest involvement of disturbed force feedback. Assessment of sensorimotor...

journal article 2013

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Control of thumb force using surface functional electrical stimulation and muscle load sharing

Westerveld, A.J. (author), Schouten, A.C. (author), Veltink, P.H. (author), Van der Kooij, H. (author)

Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of individual muscle forces, described by a sigmoidal...

journal article 2013

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Electrical vestibular stimuli to enhance vestibulo-motor output and improve subject comfort

Forbes, P.A. (author), Dakin, C.J. (author), Geers, A.M. (author), Vlaar, M.P. (author), Happee, R. (author), Siegmund, G.P. (author), Schouten, A.C. (author), Blouin, J.S. (author)

Electrical vestibular stimulation is often used to assess vestibulo-motor and postural responses in both clinical and research settings. Stochastic vestibular stimulation (SVS) is a recently established technique with many advantages over its square-wave counterpart; however, the evoked muscle responses remain relatively small. Although the...

journal article 2014

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Evaluation of EMG, force and joystick as control interfaces for active arm supports

Lobo-Prat, J. (author), Keemink, A.Q.L. (author), Stienen, A.H.A. (author), Schouten, A.C. (author), Veltink, P.H. (author), Koopman, B.F.J.M. (author)

Background: The performance capabilities and limitations of control interfaces for the operation of active movement-assistive devices remain unclear. Selecting an optimal interface for an application requires a thorough understanding of the performance of multiple control interfaces. Methods: In this study the performance of EMG-, force- and...

journal article 2014

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Task, muscle and frequency dependent vestibular control of posture

Forbes, P.A. (author), Siegmund, G.P. (author), Schouten, A.C. (author), Blouin, J.S. (author)

The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in...

journal article 2015

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NeuroControl of movement: System identification approach for clinical benefit

Meskers, C.G.M. (author), De Groot, J. (author), De Vlugt, E. (author), Schouten, A.C. (author)

Progress in diagnosis and treatment of movement disorders after neurological diseases like stroke, cerebral palsy (CP), dystonia and at old age requires understanding of the altered capacity to adequately respond to physical obstacles in the environment. With posture and movement disorders, the control of muscles is hampered, resulting in...

journal article 2015

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Dynamic functional brain connectivity for face perception

Yang, Y. (author), Qiu, Y. (author), Schouten, A.C. (author)

journal article 2015