Approaches to human arm movement control—A review

2009 ◽  
Vol 33 (1) ◽  
pp. 69-77 ◽  
Author(s):  
F.M.M.O. Campos ◽  
J.M.F. Calado
Keyword(s):  
Movement Control ◽  
Arm Movement ◽  
Human Arm

Modeling of Relative Damping in Defining the Equilibrium Point Trajectory for the Human Arm Movement Control

2008 ◽  
Author(s):  
Kai Chen ◽  
Richard A. Foulds ◽  
Sergei Adamovich ◽  
Qinyin Qiu ◽  
Katharine Swift
Keyword(s):  
Equilibrium Point ◽  
Inverse Kinematics ◽  
Movement Control ◽  
Arm Movement ◽  
Forward Kinematics ◽  
The Novel ◽  
Upper Arm ◽  
Shoulder Joints ◽  
Human Arm ◽  
Damping Model

Existing research suggests that limb motion can be represented as an Equilibrium Point (EP) trajectory in combination with a trajectory that reflects specified damping and stiffness at each joint. This model utilizes the concept of relative damping, an integral factor in defining the Equilibrium Point trajectory, to help maintain stability during the arm movement. By using commercialized Flock of Bird® (FOB) sensor, we can obtain experimental trajectories and angular information for human elbow and shoulder joints, as well as forearm and upper arm position during reaching in slow and fast movements. We replaced the complicated inverse kinematics computation of brain with our simple relative damping model, and then calculated the EP trajectories of the elbow and shoulder to use as inputs to our following forward kinematics model. The model generated trajectories which closely match the experimental data. The novel features of this model include the EP trajectory input generated by relative damping. Therefore, we conclude that multi-joint manipulations can be modeled by an appropriate EP trajectory along with relative damping.

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

Does visually induced self-motion affect grip force when holding an object?

2012 ◽  
Vol 108 (6) ◽  
pp. 1685-1694 ◽  
Author(s):  
Lionel Bringoux ◽  
Jean-Claude Lepecq ◽  
Frédéric Danion
Keyword(s):  
Grip Force ◽  
Movement Control ◽  
Arm Movement ◽  
Object Motion ◽  
Oscillatory Motion ◽  
Constant Speed ◽  
Main Task ◽  
Spectral Analyses ◽  
Arm Motion ◽  
Self Motion

Accurate control of grip force during object manipulation is necessary to prevent the object from slipping, especially to compensate for the action of gravitational and inertial forces resulting from hand/object motion. The goal of the current study was to assess whether the control of grip force was influenced by visually induced self-motion (i.e., vection), which would normally be accompanied by changes in object load. The main task involved holding a 400-g object between the thumb and the index finger while being seated within a virtual immersive environment that simulated the vertical motion of an elevator across floors. Different visual motions were tested, including oscillatory (0.21 Hz) and constant-speed displacements of the virtual scene. Different arm-loading conditions were also tested: with or without the hand-held object and with or without oscillatory arm motion (0.9 Hz). At the perceptual level, ratings from participants showed that both oscillatory and constant-speed motion of the elevator rapidly induced a long-lasting sensation of self-motion. At the sensorimotor level, vection compellingness altered arm movement control. Spectral analyses revealed that arm motion was entrained by the oscillatory motion of the elevator. However, we found no evidence that grip force used to hold the object was visually affected. Specifically, spectral analyses revealed no component in grip force that would mirror the virtual change in object load associated with the oscillatory motion of the elevator, thereby allowing the grip-to-load force coupling to remain unaffected. Altogether, our findings show that the neural mechanisms underlying vection interfere with arm movement control but do not interfere with the delicate modulation of grip force. More generally, those results provide evidence that the strength of the coupling between the sensorimotor system and the perceptual level can be modulated depending on the effector.

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.

The Role of Robotic Path Assistance and Weight Support in Facilitating 3D Movements in Individuals With Poststroke Hemiparesis

2020 ◽  
Vol 34 (2) ◽  
pp. 134-147
Author(s):  
Preeti Raghavan ◽  
Seda Bilaloglu ◽  
Syed Zain Ali ◽  
Xin Jin ◽  
Viswanath Aluru ◽  
...  
Keyword(s):  
Scale Score ◽  
Motor Impairment ◽  
Movement Control ◽  
Arm Movement ◽  
Random Order ◽  
Healthy Controls ◽  
High Functioning ◽  
Weight Support ◽  
Speed Error ◽  
Low Functioning

Background. High-intensity repetitive training is challenging to provide poststroke. Robotic approaches can facilitate such training by unweighting the limb and/or by improving trajectory control, but the extent to which these types of assistance are necessary is not known. Objective. The purpose of this study was to examine the extent to which robotic path assistance and/or weight support facilitate repetitive 3D movements in high functioning and low functioning subjects with poststroke arm motor impairment relative to healthy controls. Methods. Seven healthy controls and 18 subjects with chronic poststroke right-sided hemiparesis performed 300 repetitions of a 3D circle-drawing task using a 3D Cable-driven Arm Exoskeleton (CAREX) robot. Subjects performed 100 repetitions each with path assistance alone, weight support alone, and path assistance plus weight support in a random order over a single session. Kinematic data from the task were used to compute the normalized error and speed as well as the speed-error relationship. Results. Low functioning stroke subjects (Fugl-Meyer Scale score = 16.6 ± 6.5) showed the lowest error with path assistance plus weight support, whereas high functioning stroke subjects (Fugl-Meyer Scale score = 59.6 ± 6.8) moved faster with path assistance alone. When both speed and error were considered together, low functioning subjects significantly reduced their error and increased their speed but showed no difference across the robotic conditions. Conclusions. Robotic assistance can facilitate repetitive task performance in individuals with severe arm motor impairment, but path assistance provides little advantage over weight support alone. Future studies focusing on antigravity arm movement control are warranted poststroke.

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.

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