Related Experiment Video
Updated: May 20, 2026
06:31
Force and Position Control in Humans - The Role of Augmented Feedback
Published on: June 19, 2016
Force and time gain interact to nonlinearly scale adaptive visual-motor isometric force control
1Department of Kinesiology, The Pennsylvania State University, 266 Rec Bldg, University Park, PA 16802, USA. xiaogang.hu@northwestern.edu
Experimental Brain Research
|July 17, 2012
Summary
Optimal isometric force control depends on a balance of force and time gains. Moderate force-time gain combinations enhance performance, with task demands influencing this relationship.
Area of Science:
- Motor Control
- Human Factors Engineering
- Biomechanics
Background:
- Visual feedback is crucial for motor control.
- Understanding how visual gain parameters affect force production is important for human-computer interaction and rehabilitation.
Purpose of the Study:
- To investigate the influence of force-time gain on visual-motor control of isometric force.
- To determine how different task demands (constant vs. sinewave) affect the optimal force-time gain relationship.
Main Methods:
- Subjects performed isometric index finger abduction to target forces (20% MVC).
- Visual feedback gains for force and time were manipulated (compressed/extended) in a crossed fashion.
- Performance was assessed under constant and sinewave force production tasks.
Main Results:
- A U-shaped relationship was observed between force-time gain and force performance, indicating an optimal moderate gain combination.
- The interaction between force and time gains differed based on task demand.
- For constant force tasks, optimal gains in one dimension were independent of the other; for sinewave tasks, they were interdependent.
Conclusions:
- Force control is constrained by the interaction of visual information gain, force dynamics, and task demands.
- Findings suggest specific visual gain parameter settings for adaptive force control systems.
More Related Videos
Related Concept Videos
01:20Motor Unit Stimulation
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
01:07Time-Domain Interpretation of PD Control
Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization.
Consider the example of control of motor torque. Initially, a positive...
Consider the example of control of motor torque. Initially, a positive...
01:30Three-Dimensional Force System:Problem Solving
A three-dimensional force system refers to a scenario in which three forces act simultaneously in three different directions. This type of problem is commonly encountered in physics and engineering, where it is necessary to calculate the resultant force on the system, which can then be used to predict or analyze the behavior of the object or structure under consideration.
To solve a three-dimensional force system, first resolve each force into its respective scalar components. Do this using...
To solve a three-dimensional force system, first resolve each force into its respective scalar components. Do this using...
00:57Power Expended by a Constant Force
The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may have the same velocity when they reach the finish line, therefore doing the same amount of work, but the winner does it in the least amount of time. Thus, power is defined as the rate of doing work. Since work can vary as a function of time, the average power is defined as the work done during a time interval, divided by the time interval.
01:22Muscle Stimulation Frequency
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
01:05Static and Kinetic Frictional Force
One of the simpler characteristics of sliding friction is that it is parallel to the contact surfaces between systems, and is always in a direction that opposes the motion or attempted motion of the systems relative to each other. If two systems are in contact and moving relative to one another, then the friction between them is called kinetic friction. For example, kinetic friction slows a hockey puck sliding on ice.
However, if two systems are in contact and are stationary relative to one...
However, if two systems are in contact and are stationary relative to one...