Journal Article HUMAN ARM TRAJECTORY FORMATION Get access W. ABEND, ABEND Department of Psychology, Massachusetts Institute TechnologyCambridge, MA 02139Department Neurology, Harvard Medical SchoolBoston, 02115Division Medicine, Brigham and Women's HospitalBoston, 02115, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar E. BIZZI, BIZZI P. MORASSO 1 Present address: Istituto di Elettrotecnica, Viale Causa 13, 16145 Genova, Italy. Brain, Volume 105, Issue 2,...

The studies reported here are directed toward understanding some of the mechanisms whereby central nervous system terminates a given phase in motor sequence and maintains newly acquired position. In particular, we investigated extent to which termination centrally initiated head movement monkeys subsequent maintenance posture depend on readout proprioceptive afferent input generated during itself or instead programmed. We approached this question two ways: first, using vestibulectomized, but...

1. We have investigated the relative contributions of mechanical and reflex mechanisms in generating forces produced by neck muscles when loads were unexpectedly applied during centrally programmed head movements monkeys. These movements, subserved well endowed with muscle spindles, are part coordinated eye-head response to appearance a stimulus animal's visual field. Our preparation was chronically vestibulectomized monkey trained make discrimination. 2. Two procedures used evaluate torque...

The main purpose of this study is to compare two different feedback controllers for the stabilization quiet standing in humans, taking into account that intrinsic ankle stiffness insufficient and there a large delay inducing instability loop: 1) standard linear, continuous-time PD controller 2) an intermittent characterized by switching function defined phase plane, with or without dead zone around nominal equilibrium state. stability analysis first carried out using tools linear control...

In order to identify useful guidelines for the clinical practitioner as regards use of static posturographic analysis, we collected a set posrurograms from 3 groups participants (normal participants. Parkinsonian patients, and osteoporotic patients), according Romberg test. From each posturogram, extracted global parameters (in time domain frequency domain) structural (based on diffusion plots sway-density plots), with total 38 parameters. The discriminative power parameter was evaluated by...

This communication addresses again the hypothesis that stabilization of balance during quiet standing is achieved by stiffness ankle muscles without anticipatory active control. It shown a recently proposed method estimating directly from analysis posturographic data incorrect because it ignores modulation motoneuronal activity and grossly overestimates real range values in relation with critical value stiffness. Moreover, new simulation study realistic model demonstrates mechanical...

Human upright posture, as a mechanical system, is characterized by an instability of saddle type, involving both stable and unstable dynamic modes. The brain stabilizes such system generating active joint torques, according to time-delayed neural feedback control. What still unsolved clear understanding the control strategies mechanisms that are used central nervous in order stabilize posture robust way while maintaining flexibility. Most studies this direction have been limited single...

This technical note describes a new robotic workstation for neurological rehabilitation, shortly named Braccio di Ferro. It has been designed by having in mind the range of forces and frequency bandwidth that characterize interaction between

The aim of this paper is to outline a model the eye-head system and some its control strategies. To formulate such model, was stimulated with random or periodic visual targets. Coupling between eye head motor commands evident in experiments performed, also found be case for acoustic tactile stimuli. Further were performed investigate whether central nervous (CNS) would able overcome relative lack offlexibility shown by initially proposed. These experiments, which it required execute...

The time course of the center pressure (CoP) during human quiet standing, corresponding to body sway, is a stochastic process, influenced by variety features underlying neuro-musculo-skeletal system, such as postural stability and flexibility. Due complexity sway patterns have been characterized in an empirical way number indices, size mean velocity. Here, we describe statistical approach with aim estimating "universal" namely parameters that are independent individual characteristics thus...

In the study of balance and postural control (Single) Inverted Pendulum model (SIP) has been taken for a long time as an acceptable paradigm, with implicit assumption that only ankle rotations are relevant describing explaining sway movements. However, more recent kinematic analysis quiet standing revealed hip motion cannot be neglected at all ankle-hip oscillatory patterns characterized by complex in-phase anti-phase interactions, suggesting SIP should substituted DIP (Double Pendulum)...

The trend in industrial/service robotics is to develop robots that can cooperate with people, interacting them an autonomous, safe and purposive way. These are the fundamental elements characterizing fourth fifth industrial revolutions (4IR, 5IR): crucial innovation adoption of intelligent technologies allow development cyber-physical systems , similar if not superior humans. common wisdom intelligence might be provided by AI (Artificial Intelligence), a claim supported more media coverage...