Faculty Opinions recommendation of Are complex control signals required for human arm movement?

2017 ◽  
Author(s):  
Neville Hogan
Keyword(s):  
Arm Movement ◽  
Complex Control ◽  
Control Signals ◽  
Human Arm

Are Complex Control Signals Required for Human Arm Movement?

1998 ◽  
Vol 79 (3) ◽  
pp. 1409-1424 ◽  
Author(s):  
Paul L. Gribble ◽  
David J. Ostry ◽  
Vittorio Sanguineti ◽  
Rafael Laboissière
Keyword(s):  
Joint Stiffness ◽  
Arm Movement ◽  
Movement Speed ◽  
Muscle Properties ◽  
Complex Control ◽  
Equilibrium Trajectory ◽  
Control Signals ◽  
Human Arm ◽  
Constant Rate ◽  
Arm Motion

Gribble, Paul L., David J. Ostry, Vittorio Sanguineti, and Rafael Laboissière. Are complex control signals required for human arm movement? J. Neurophysiol. 79: 1409–1424, 1998. It has been proposed that the control signals underlying voluntary human arm movement have a “complex” nonmonotonic time-varying form, and a number of empirical findings have been offered in support of this idea. In this paper, we address three such findings using a model of two-joint arm motion based on the λ version of the equilibrium-point hypothesis. The model includes six one- and two-joint muscles, reflexes, modeled control signals, muscle properties, and limb dynamics. First, we address the claim that “complex” equilibrium trajectories are required to account for nonmonotonic joint impedance patterns observed during multijoint movement. Using constant-rate shifts in the neurally specified equilibrium of the limb and constant cocontraction commands, we obtain patterns of predicted joint stiffness during simulated multijoint movements that match the nonmonotonic patterns reported empirically. We then use the algorithm proposed by Gomi and Kawato to compute a hypothetical equilibrium trajectory from simulated stiffness, viscosity, and limb kinematics. Like that reported by Gomi and Kawato, the resulting trajectory was nonmonotonic, first leading then lagging the position of the limb. Second, we address the claim that high levels of stiffness are required to generate rapid single-joint movements when simple equilibrium shifts are used. We compare empirical measurements of stiffness during rapid single-joint movements with the predicted stiffness of movements generated using constant-rate equilibrium shifts and constant cocontraction commands. Single-joint movements are simulated at a number of speeds, and the procedure used by Bennett to estimate stiffness is followed. We show that when the magnitude of the cocontraction command is scaled in proportion to movement speed, simulated joint stiffness varies with movement speed in a manner comparable with that reported by Bennett. Third, we address the related claim that nonmonotonic equilibrium shifts are required to generate rapid single-joint movements. Using constant-rate equilibrium shifts and constant cocontraction commands, rapid single-joint movements are simulated in the presence of external torques. We use the procedure reported by Latash and Gottlieb to compute hypothetical equilibrium trajectories from simulated torque and angle measurements during movement. As in Latash and Gottlieb, a nonmonotonic function is obtained even though the control signals used in the simulations are constant-rate changes in the equilibrium position of the limb. Differences between the “simple” equilibrium trajectory proposed in the present paper and those that are derived from the procedures used by Gomi and Kawato and Latash and Gottlieb arise from their use of simplified models of force generation.

Minimum muscle tension-change model for human arm movement

1990 ◽  
Vol 11 ◽  
pp. S54 ◽  
Author(s):  
Yoji Uno ◽  
Mitsuo Kawato ◽  
Ryoji Suzuki
Keyword(s):  
Muscle Tension ◽  
Arm Movement ◽  
Change Model ◽  
Human Arm ◽  
Tension Change

scholarly journals Evaluation of a Bio-impedance Method for Measuring Human Arm Movement

2002 ◽  
Vol 43 (5) ◽  
pp. 637 ◽  
Author(s):  
Jong Chan Kim ◽  
Soo Chan Kim ◽  
Ki Chang Nam ◽  
Seon Hui Ahn ◽  
Mignon Park ◽  
...  
Keyword(s):  
Arm Movement ◽  
Impedance Method ◽  
Human Arm

Experimental Study and Modeling of Equilibrium Point Trajectory Control in Single and Double-Joint Arm Movements

2009 ◽  
Author(s):  
Kai Chen ◽  
Richard A. Foulds ◽  
Katharine Swift ◽  
Sergei Adamovich
Keyword(s):  
Equilibrium Point ◽  
Time Delays ◽  
Arm Movement ◽  
Neuromuscular Control ◽  
Muscle Stimulation ◽  
Time Varying ◽  
Shoulder Joints ◽  
Human Arm ◽  
Neural Transmission ◽  
Human Joint

This paper discusses a new model of neuromuscular control of elbow and shoulder joints based on the Equilibrium Point Hypothesis (EPH). The earlier model [1] suggests that the incorporation of relative damping within reflex loops can maintain the dynamic simplicity of the EPH, while being robust over the range of human joint velocities. The model presented here, extends previous work with the use of experimental Electromyography data of 2 muscles to determine the timing parameters of the virtual trajectories and the inclusion of physiological time delays to account for neural transmission and muscle stimulation/activation delays. This model uses delays presented in the literature by other researchers, with a goal of contributing to a resolution of arguments regarding the controversial arguments in the planning sequences. Therefore, this study attempts to demonstrate the possibility for using descending CNS signals to represent relatively simple, monotonic virtual trajectories of the time varying Equilibrium Point for the control of human arm movement. In addition, the study demonstrates that these virtual trajectories were robust enough to control and coordinated movement of elbow and shoulder joints discussed.

Directional Control of Planar Human Arm Movement

1997 ◽  
Vol 78 (6) ◽  
pp. 2985-2998 ◽  
Author(s):  
Gerald L. Gottlieb ◽  
Qilai Song ◽  
Gil L. Almeida ◽  
Di-An Hong ◽  
Daniel Corcos
Keyword(s):  
Control System ◽  
Arm Movement ◽  
Initial Position ◽  
Joint Torque ◽  
Reaching Movements ◽  
Rule Based ◽  
Joint Torques ◽  
Directional Control ◽  
Human Arm ◽  
Dynamic Components

Gottlieb, Gerald L., Qilai Song, Gil L. Almeida, Di-an Hong, and Daniel Corcos. Directional control of planar human arm movement. J. Neurophysiol. 78: 2985–2998, 1997. We examined the patterns of joint kinematics and torques in two kinds of sagittal plane reaching movements. One consisted of movements from a fixed initial position with the arm partially outstretched, to different targets, equidistant from the initial position and located according to the hours of a clock. The other series added movements from different initial positions and directions and >40–80 cm distances. Dynamic muscle torque was calculated by inverse dynamic equations with the gravitational components removed. In making movements in almost every direction, the dynamic components of the muscle torques at both the elbow and shoulder were related almost linearly to each other. Both were similarly shaped, biphasic, almost synchronous and symmetrical pulses. These findings are consistent with our previously reported observations, which we termed a linear synergy. The relative scaling of the two joint torques changes continuously and regularly with movement direction. This was confirmed by calculating a vector defined by the dynamic components of the shoulder and elbow torques. The vector rotates smoothly about an ellipse in intrinsic, joint torque space as the direction of hand motion rotates about a circle in extrinsic Cartesian space. This confirms a second implication of linear synergy that the scaling constant between the linearly related joint torques is directionally dependent. Multiple linear regression showed that the torque at each joint scales as a simple linear function of the angular displacement at both joints, in spite of the complex nonlinear dynamics of multijoint movement. The coefficients of this function are independent of the initial arm position and movement distance and are the same for all subjects. This is an unanticipated finding. We discuss these observations in terms of the hypothesis that voluntary, multiple degrees of freedom, rapid reaching movements may use rule-based, feed-forward control of dynamic joint torque. Rule-based control of joint torque with separate dynamic and static controllers is an alternative to models such as those based on the equilibrium point hypotheses that rely on a positionally based controller to produce both dynamic and static torque components. It is also an alternative to feed-forward models that directly solve the problems of inverse dynamics. Our experimental findings are not necessarily incompatible with any of the alternative models, but they describe new, additional findings for which we need to account. The rules are chosen by the nervous system according to features of the kinematic task to couple muscle contraction at the shoulder and elbow in a linear synergy. Speed and load control preserves the relative magnitudes of the dynamic torques while directional control is accomplished by modulating them in a differential manner. This control system operates in parallel with a positional control system that solves the problems of postural stability.

Human Hand Movement Analysis Using Principle Component Analysis Classifier

2013 ◽  
Vol 284-287 ◽  
pp. 3126-3130 ◽  
Author(s):  
Ching Yee Yong ◽  
Rubita Sudirman ◽  
Nasrul Humaimi Mahmood ◽  
Kim Mey Chew
Keyword(s):  
Hand Movement ◽  
Arm Movement ◽  
Movement Analysis ◽  
Human Motion ◽  
Human Hand ◽  
Human Arm ◽  
Set Up ◽  
And Behavior ◽  
Adequate Internal Consistency

This study investigates and acts as a trial clinical outcome for human motion and behavior analysis in order to investigate human arm movement during jogging and walking. It was developed to analyze and access the quality of human motion that can be used in hospitals, clinics and human motion researches. It aims to establish how widespread the movement and motion of arm will bring to effect of human in life. An experiment was set up in a laboratory environment with conjunction of analyzing human motion and its behavior. The instruments demonstrate adequate internal consistency of optimum scatter plot in gyroscope and accelerometer for pattern classification. PCA used in this study was successfully differentiate and classify

Predicting Any Arm Movement Feedback to Induce Three-Dimensional Illusory Movements in Humans

2010 ◽  
Vol 104 (2) ◽  
pp. 949-959 ◽  
Author(s):  
Chloé Thyrion ◽  
Jean-Pierre Roll
Keyword(s):  
Three Dimensional ◽  
Arm Movements ◽  
Arm Movement ◽  
Muscle Spindles ◽  
Proprioceptive Information ◽  
Human Arm ◽  
Muscle Groups ◽  
Coding Rules ◽  
Straight Lines ◽  
2D And 3D

Our sense of body posture and movement is mainly mediated by densely packed populations of tiny mechanoreceptors present in the muscles. Signals triggered in muscle spindles by our own actions contribute crucially to our consciousness of positions and movements by continuously feeding and updating dynamic sensorimotor maps. Deciphering the coding rules whereby the nervous system integrates this proprioceptive information perceptually could help to elucidate the mechanisms underlying kinesthesia. The aim of the present study was to test the validity of a “propriomimetic method” of predicting the proprioceptive streams emitted by each of the muscles involved in two- (2D) and three-dimensional (3D) arm movements. This method was based on the functional properties of muscle spindle populations previously recorded microneurographically in behaving humans. Ia afferent patterns mimicking those evoked when the “arm–forearm” ensemble is drawing straight lines, graphic symbols, and complex 3D figures were calculated. These simulated patterns were then delivered to the main elbow and shoulder muscle tendons of motionless volunteers via a set of vibrators. Results show that the simulated proprioceptive patterns applied induced, in passive subjects, illusory 2D and 3D arm movements, the trajectories of which were very similar to the expected ones. These simulated patterns can therefore be said to be a substitute for the Ia proprioceptive feedback evoked by any human arm movement and this method can certainly be extended to other musculoskeletal ensembles. The illusory movements induced when these proprioceptive patterns are applied to muscle groups via sets of vibrators may provide useful tools for sensorimotor rehabilitation purposes.

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